From 67af1ba10a8f39a5f14b7290b5bbc46760816f58 Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Mon, 21 Jan 2019 21:15:14 +0100
Subject: [PATCH 01/11] Reorder exercises according to Round 1
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

As part of the ongoing curriculum update, this re-orders the core exercises according to perceived difficulty. Most notably, this moves simple-cipher down -- re-orders the list loosly according to this:

hello-world, gigasecond, leap, rna-transcription, bob, pangram, space-age, matrix, linked-list, grade-school, robot-name, pascals-triangle, simple-cipher, wordy, secret-handshake, list-ops

Since it's a bit weird to introduce Date thát early, it's placed after leap --- for now.

Furthermore this moves all the core exercises to the top and all the side exercises unlocked by these below that, in order. The bonus exercises (always unlocked) are at the bottom.
---
 config.json | 1326 +++++++++++++++++++++++++--------------------------
 1 file changed, 663 insertions(+), 663 deletions(-)

diff --git a/config.json b/config.json
index 5c513e6298..42ca9fef08 100644
--- a/config.json
+++ b/config.json
@@ -4,47 +4,6 @@
   "blurb": "JavaScript is a scripting language, primarily used for creating dynamic websites and programming web servers. It's a very popular language, and supports a variety of programming paradigms.",
   "test_pattern": ".*[.]spec[.]js$",
   "exercises": [
-    {
-      "slug": "zipper",
-      "uuid": "fd1575f3-3087-4cfa-8a26-168fba6d0606",
-      "core": false,
-      "unlocked_by": null,
-      "difficulty": 8,
-      "topics": [
-        "recursion",
-        "searching",
-        "trees"
-      ]
-    },
-    {
-      "slug": "point-mutations",
-      "uuid": "6d43709b-3809-4a6a-ab41-2a5ab841b5fb",
-      "core": false,
-      "unlocked_by": null,
-      "difficulty": 0,
-      "topics": null,
-      "deprecated": true
-    },
-    {
-      "slug": "forth",
-      "uuid": "e4035939-4375-4720-87ae-e613f925f013",
-      "core": false,
-      "unlocked_by": "matrix",
-      "difficulty": 8,
-      "topics": [
-        "domain_specific_languages",
-        "parsing",
-        "stacks"
-      ]
-    },
-    {
-      "slug": "darts",
-      "uuid": "6c64649b-ea81-4118-9e74-a0a55018ffbc",
-      "core": false,
-      "unlocked_by": null,
-      "difficulty": 3,
-      "topics": null
-    },
     {
       "slug": "hello-world",
       "uuid": "9ce0f408-6d7b-4466-a390-75aeaf9492f2",
@@ -72,15 +31,13 @@
       ]
     },
     {
-      "slug": "reverse-string",
-      "uuid": "e84c97eb-dbec-487c-b99f-ae9924e16293",
-      "core": false,
-      "unlocked_by": "leap",
+      "slug": "gigasecond",
+      "uuid": "fd7b62d4-266b-4e84-a526-bf3d47901216",
+      "core": true,
+      "unlocked_by": null,
       "difficulty": 2,
       "topics": [
-        "for",
-        "loops",
-        "strings"
+        "time"
       ]
     },
     {
@@ -95,19 +52,18 @@
       ]
     },
     {
-      "slug": "simple-cipher",
-      "uuid": "62d60b42-93bc-4de9-90d1-1ca18a847812",
+      "slug": "bob",
+      "uuid": "a5bf36f0-5d3c-41d4-8d54-e37e484e59cd",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 1,
+      "difficulty": 2,
       "topics": [
-        "algorithms",
         "control_flow_conditionals",
-        "control_flow_loops",
-        "randomness",
+        "pattern_recognition",
+        "polymorfism",
+        "regular_expressions",
         "strings",
-        "text_formatting",
-        "transforming"
+        "unicode"
       ]
     },
     {
@@ -126,31 +82,6 @@
         "strings"
       ]
     },
-    {
-      "slug": "bob",
-      "uuid": "a5bf36f0-5d3c-41d4-8d54-e37e484e59cd",
-      "core": true,
-      "unlocked_by": null,
-      "difficulty": 2,
-      "topics": [
-        "control_flow_conditionals",
-        "pattern_recognition",
-        "polymorfism",
-        "regular_expressions",
-        "strings",
-        "unicode"
-      ]
-    },
-    {
-      "slug": "gigasecond",
-      "uuid": "fd7b62d4-266b-4e84-a526-bf3d47901216",
-      "core": true,
-      "unlocked_by": null,
-      "difficulty": 2,
-      "topics": [
-        "time"
-      ]
-    },
     {
       "slug": "space-age",
       "uuid": "d9d757ed-ebe6-4d4a-aa73-f6834221cd54",
@@ -162,37 +93,6 @@
         "floating_point_numbers"
       ]
     },
-    {
-      "slug": "binary",
-      "uuid": "0ba4d3b9-2519-49ac-bd93-f960aca6c11f",
-      "core": false,
-      "unlocked_by": null,
-      "difficulty": 4,
-      "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "exception_handling",
-        "integers",
-        "mathematics",
-        "regular_expressions",
-        "strings"
-      ],
-      "deprecated": true
-    },
-    {
-      "slug": "prime-factors",
-      "uuid": "f43cdddf-eea8-4c4a-8359-c69e20ff9661",
-      "core": true,
-      "unlocked_by": null,
-      "difficulty": 4,
-      "topics": [
-        "algorithms",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "integers",
-        "math"
-      ]
-    },
     {
       "slug": "matrix",
       "uuid": "dd0b5e67-81f6-437e-8334-2ec0dfeb862a",
@@ -225,58 +125,59 @@
       ]
     },
     {
-      "slug": "pascals-triangle",
-      "uuid": "99493160-4673-402f-acda-62db5378148d",
+      "slug": "grade-school",
+      "uuid": "64637322-33bc-401f-8cec-1f9810a41f75",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 5,
+      "difficulty": 6,
       "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "math",
-        "strings",
-        "text_formatting"
+        "arrays",
+        "maps",
+        "sorting"
       ]
     },
     {
-      "slug": "secret-handshake",
-      "uuid": "74bbc9e3-edc5-41e0-84d7-5b2d98dd8370",
+      "slug": "robot-name",
+      "uuid": "03f4dfea-e6db-4754-b2c8-ca06c8b81ef1",
       "core": true,
       "unlocked_by": null,
       "difficulty": 6,
       "topics": [
-        "algorithms",
-        "arrays",
-        "bitwise_operations",
         "control_flow_conditionals",
-        "control_flow_loops",
-        "games"
+        "exception_handling",
+        "randomness",
+        "regular_expressions",
+        "sets"
       ]
     },
     {
-      "slug": "grade-school",
-      "uuid": "64637322-33bc-401f-8cec-1f9810a41f75",
+      "slug": "pascals-triangle",
+      "uuid": "99493160-4673-402f-acda-62db5378148d",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 6,
+      "difficulty": 5,
       "topics": [
-        "arrays",
-        "maps",
-        "sorting"
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "math",
+        "strings",
+        "text_formatting"
       ]
     },
     {
-      "slug": "robot-name",
-      "uuid": "03f4dfea-e6db-4754-b2c8-ca06c8b81ef1",
+      "slug": "simple-cipher",
+      "uuid": "62d60b42-93bc-4de9-90d1-1ca18a847812",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 6,
+      "difficulty": 1,
       "topics": [
+        "algorithms",
         "control_flow_conditionals",
-        "exception_handling",
+        "control_flow_loops",
         "randomness",
-        "regular_expressions",
-        "sets"
+        "strings",
+        "text_formatting",
+        "transforming"
       ]
     },
     {
@@ -295,6 +196,21 @@
         "strings"
       ]
     },
+    {
+      "slug": "secret-handshake",
+      "uuid": "74bbc9e3-edc5-41e0-84d7-5b2d98dd8370",
+      "core": true,
+      "unlocked_by": null,
+      "difficulty": 6,
+      "topics": [
+        "algorithms",
+        "arrays",
+        "bitwise_operations",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "games"
+      ]
+    },
     {
       "slug": "list-ops",
       "uuid": "7d9db056-5398-41b6-af3b-9707f5eb0dbc",
@@ -323,72 +239,83 @@
       ]
     },
     {
-      "slug": "hamming",
-      "uuid": "d773c4ef-c09e-40e4-a7fe-01456cb4a12a",
+      "slug": "reverse-string",
+      "uuid": "e84c97eb-dbec-487c-b99f-ae9924e16293",
       "core": false,
-      "unlocked_by": "rna-transcription",
+      "unlocked_by": "leap",
       "difficulty": 2,
       "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "equality",
+        "for",
+        "loops",
         "strings"
       ]
     },
     {
-      "slug": "isogram",
-      "uuid": "3df577af-2854-40ee-b211-9b608dbbad58",
+      "slug": "triangle",
+      "uuid": "ed3ca73a-a0f0-46b8-8013-8b6d20758c8f",
       "core": false,
-      "unlocked_by": "pangram",
-      "difficulty": 2,
+      "unlocked_by": "leap",
+      "difficulty": 3,
       "topics": [
-        "filtering",
-        "strings"
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "exception_handling",
+        "integers"
       ]
     },
     {
-      "slug": "beer-song",
-      "uuid": "6573f168-d8fc-4ccf-a864-1a61f432fae1",
+      "slug": "collatz-conjecture",
+      "uuid": "b8dacb3a-51d0-4da7-a6d2-aa29867e2b8c",
       "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 5,
+      "unlocked_by": "leap",
+      "difficulty": 3,
       "topics": [
         "control_flow_conditionals",
         "control_flow_loops",
-        "strings"
+        "exception_handling",
+        "integers",
+        "math",
+        "recursion"
       ]
     },
     {
-      "slug": "phone-number",
-      "uuid": "82775adb-eabe-4d44-91f5-4080b8834a4a",
+      "slug": "clock",
+      "uuid": "4e0e2c30-be33-49b6-b196-213888a93a0c",
       "core": false,
-      "unlocked_by": "pangram",
-      "difficulty": 3,
+      "unlocked_by": "gigasecond",
+      "difficulty": 5,
       "topics": [
-        "parsing",
-        "transforming"
+        "dates",
+        "globalization",
+        "time"
       ]
     },
     {
-      "slug": "anagram",
-      "uuid": "309fa4f1-e03a-4ab2-b371-cdf742501cf7",
+      "slug": "meetup",
+      "uuid": "98617798-b49d-4d43-9f65-7131ee73d626",
       "core": false,
-      "unlocked_by": "pangram",
-      "difficulty": 1,
+      "unlocked_by": "gigasecond",
+      "difficulty": 7,
       "topics": [
-        "filtering",
-        "strings"
-      ]
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "dates",
+        "equality",
+        "exception_handling",
+        "time"
+      ]
     },
     {
-      "slug": "food-chain",
-      "uuid": "62672dc7-e827-4c2e-a282-d6df45b60bbd",
+      "slug": "hamming",
+      "uuid": "d773c4ef-c09e-40e4-a7fe-01456cb4a12a",
       "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 4,
+      "unlocked_by": "rna-transcription",
+      "difficulty": 2,
       "topics": [
-        "algorithms",
-        "text_formatting"
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "equality",
+        "strings"
       ]
     },
     {
@@ -405,325 +332,305 @@
       ]
     },
     {
-      "slug": "sublist",
-      "uuid": "4be85b5e-6b13-11e7-907b-a6006ad3dba0",
+      "slug": "scrabble-score",
+      "uuid": "11771d47-1109-4579-a62b-e0b8e9583485",
       "core": false,
-      "unlocked_by": "linked-list",
-      "difficulty": 4,
+      "unlocked_by": "rna-transcription",
+      "difficulty": 5,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "maps",
+        "strings"
+      ]
+    },
+    {
+      "slug": "raindrops",
+      "uuid": "f77ac2d1-cf3a-497d-bf04-b484a5a9cb37",
+      "core": false,
+      "unlocked_by": "rna-transcription",
+      "difficulty": 2,
+      "topics": [
+        "control_flow_conditionals",
+        "integers",
+        "strings",
+        "transforming"
+      ]
+    },
+    {
+      "slug": "allergies",
+      "uuid": "9d33d21c-e695-427f-9f58-dd9498d61318",
+      "core": false,
+      "unlocked_by": "rna-transcription",
+      "difficulty": 6,
       "topics": [
         "arrays",
-        "lists"
+        "bitwise_operations",
+        "control_flow_conditionals",
+        "control_flow_loops"
       ]
     },
     {
-      "slug": "word-search",
-      "uuid": "0125f5a7-8883-4553-a6c1-45f19544af5e",
+      "slug": "nucleotide-count",
+      "uuid": "be6f3ab3-1593-4c2d-8a35-5f39c1d5c91f",
       "core": false,
-      "unlocked_by": "linked-list",
-      "difficulty": 8,
+      "unlocked_by": "rna-transcription",
+      "difficulty": 4,
       "topics": [
         "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "equality",
-        "optional_values",
-        "parsing",
+        "strings",
         "text_formatting"
       ]
     },
     {
-      "slug": "grains",
-      "uuid": "d003975a-9045-4f03-9ad9-c15db584dc13",
+      "slug": "beer-song",
+      "uuid": "6573f168-d8fc-4ccf-a864-1a61f432fae1",
       "core": false,
-      "unlocked_by": "space-age",
+      "unlocked_by": "bob",
       "difficulty": 5,
       "topics": [
+        "control_flow_conditionals",
         "control_flow_loops",
-        "integers"
+        "strings"
       ]
     },
     {
-      "slug": "triangle",
-      "uuid": "ed3ca73a-a0f0-46b8-8013-8b6d20758c8f",
+      "slug": "food-chain",
+      "uuid": "62672dc7-e827-4c2e-a282-d6df45b60bbd",
       "core": false,
-      "unlocked_by": "leap",
-      "difficulty": 3,
+      "unlocked_by": "bob",
+      "difficulty": 4,
       "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "exception_handling",
-        "integers"
+        "algorithms",
+        "text_formatting"
       ]
     },
     {
-      "slug": "collatz-conjecture",
-      "uuid": "b8dacb3a-51d0-4da7-a6d2-aa29867e2b8c",
+      "slug": "pig-latin",
+      "uuid": "16e25a38-7ce3-4ccd-b2f0-1550b837fe9b",
       "core": false,
-      "unlocked_by": "leap",
-      "difficulty": 3,
+      "unlocked_by": "bob",
+      "difficulty": 4,
       "topics": [
         "control_flow_conditionals",
         "control_flow_loops",
-        "exception_handling",
-        "integers",
-        "math",
-        "recursion"
+        "games",
+        "regular_expressions",
+        "strings",
+        "transforming"
       ]
     },
     {
-      "slug": "clock",
-      "uuid": "4e0e2c30-be33-49b6-b196-213888a93a0c",
+      "slug": "proverb",
+      "uuid": "5626f5b6-207b-458b-92b6-eff2cadb240a",
       "core": false,
-      "unlocked_by": "gigasecond",
-      "difficulty": 5,
+      "unlocked_by": "bob",
+      "difficulty": 4,
       "topics": [
-        "dates",
-        "globalization",
-        "time"
+        "arrays",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "optional_values",
+        "strings",
+        "text_formatting"
       ]
     },
     {
-      "slug": "perfect-numbers",
-      "uuid": "c6691fd2-e10d-47df-acbf-3adeac5a2f89",
+      "slug": "house",
+      "uuid": "a8b7187d-12eb-4efc-b966-87823654ccda",
       "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 3,
+      "unlocked_by": "bob",
+      "difficulty": 4,
       "topics": [
         "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "integers",
-        "math"
+        "recursion",
+        "strings"
       ]
     },
     {
-      "slug": "word-count",
-      "uuid": "0073ff9a-cd6a-43cf-b8bf-4d5d8117b81b",
+      "slug": "twelve-days",
+      "uuid": "64de1776-d5c6-43fe-9abf-7e3aa08ae342",
       "core": false,
-      "unlocked_by": "pangram",
-      "difficulty": 1,
+      "unlocked_by": "bob",
+      "difficulty": 4,
       "topics": [
+        "control_flow_conditionals",
         "control_flow_loops",
-        "lists",
+        "pattern_recognition",
+        "polymorfism",
         "regular_expressions",
-        "strings",
-        "unicode"
+        "strings"
       ]
     },
     {
-      "slug": "run-length-encoding",
-      "uuid": "6ac4ad5f-a64a-4646-91c5-169d53f289f9",
+      "slug": "say",
+      "uuid": "12989bb3-c593-4f68-bea4-e2c5b76bc3c0",
       "core": false,
-      "unlocked_by": null,
-      "difficulty": 2,
+      "unlocked_by": "bob",
+      "difficulty": 6,
       "topics": [
         "control_flow_conditionals",
+        "control_flow_loops",
         "exception_handling",
-        "parsing",
-        "pattern_recognition",
-        "regular_expressions",
+        "integers",
         "strings",
         "text_formatting"
       ]
     },
     {
-      "slug": "acronym",
-      "uuid": "440d78d1-9dea-466f-9bd4-935eed067409",
+      "slug": "isbn-verifier",
+      "uuid": "b902c746-60d1-4645-a5bc-dafadec0ef32",
       "core": false,
-      "unlocked_by": "pangram",
-      "difficulty": 2,
+      "unlocked_by": "bob",
+      "difficulty": 4,
       "topics": [
+        "control_flow_conditionals",
         "control_flow_loops",
-        "regular_expressions",
-        "strings",
-        "transforming"
+        "pattern_recognition",
+        "regular_expressions"
       ]
     },
     {
-      "slug": "scrabble-score",
-      "uuid": "11771d47-1109-4579-a62b-e0b8e9583485",
+      "slug": "isogram",
+      "uuid": "3df577af-2854-40ee-b211-9b608dbbad58",
       "core": false,
-      "unlocked_by": "rna-transcription",
-      "difficulty": 5,
+      "unlocked_by": "pangram",
+      "difficulty": 2,
       "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "maps",
+        "filtering",
         "strings"
       ]
     },
     {
-      "slug": "roman-numerals",
-      "uuid": "2fc4f834-a51c-42b8-a4d9-5263229e7648",
+      "slug": "phone-number",
+      "uuid": "82775adb-eabe-4d44-91f5-4080b8834a4a",
       "core": false,
-      "unlocked_by": null,
+      "unlocked_by": "pangram",
       "difficulty": 3,
       "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "pattern_recognition",
+        "parsing",
         "transforming"
       ]
     },
     {
-      "slug": "circular-buffer",
-      "uuid": "bf0b1f95-3425-4345-8a12-3a80d49b49c9",
+      "slug": "anagram",
+      "uuid": "309fa4f1-e03a-4ab2-b371-cdf742501cf7",
       "core": false,
-      "unlocked_by": "linked-list",
-      "difficulty": 8,
+      "unlocked_by": "pangram",
+      "difficulty": 1,
       "topics": [
-        "arrays",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "data_structures",
-        "exception_handling",
-        "lists"
+        "filtering",
+        "strings"
       ]
     },
     {
-      "slug": "react",
-      "uuid": "303c6969-9446-41aa-871a-11223a43e810",
+      "slug": "word-count",
+      "uuid": "0073ff9a-cd6a-43cf-b8bf-4d5d8117b81b",
       "core": false,
-      "unlocked_by": null,
-      "difficulty": 8,
+      "unlocked_by": "pangram",
+      "difficulty": 1,
       "topics": [
-        "algorithms",
-        "events",
-        "reactive_programming"
+        "control_flow_loops",
+        "lists",
+        "regular_expressions",
+        "strings",
+        "unicode"
       ]
     },
     {
-      "slug": "raindrops",
-      "uuid": "f77ac2d1-cf3a-497d-bf04-b484a5a9cb37",
+      "slug": "acronym",
+      "uuid": "440d78d1-9dea-466f-9bd4-935eed067409",
       "core": false,
-      "unlocked_by": "rna-transcription",
+      "unlocked_by": "pangram",
       "difficulty": 2,
       "topics": [
-        "control_flow_conditionals",
-        "integers",
+        "control_flow_loops",
+        "regular_expressions",
         "strings",
         "transforming"
       ]
     },
     {
-      "slug": "allergies",
-      "uuid": "9d33d21c-e695-427f-9f58-dd9498d61318",
+      "slug": "series",
+      "uuid": "5178ae53-5364-46c9-bee3-70e6e8a8c2e3",
       "core": false,
-      "unlocked_by": "rna-transcription",
-      "difficulty": 6,
+      "unlocked_by": "pangram",
+      "difficulty": 3,
       "topics": [
-        "arrays",
-        "bitwise_operations",
-        "control_flow_conditionals",
-        "control_flow_loops"
-      ]
-    },
-    {
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-      "uuid": "8407f9d5-7a7e-40c8-aace-a6a8294ae5e9",
-      "core": false,
-      "unlocked_by": "list-ops",
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-        "algorithms",
-        "arrays",
-        "callbacks",
-        "control_flow_conditionals",
         "control_flow_loops",
-        "filtering",
-        "lists"
+        "exception_handling",
+        "strings",
+        "text_formatting"
       ]
     },
     {
-      "slug": "atbash-cipher",
-      "uuid": "a70e6027-eebe-43a1-84a6-763faa736169",
+      "slug": "largest-series-product",
+      "uuid": "1f84305d-ea76-4fe2-9858-3b53576d683d",
       "core": false,
-      "unlocked_by": "simple-cipher",
+      "unlocked_by": "pangram",
       "difficulty": 7,
       "topics": [
-        "algorithms",
-        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
+        "exception_handling",
+        "integers",
+        "math",
         "regular_expressions",
-        "text_formatting"
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-      "difficulty": 5,
-      "topics": [
-        "algorithms",
-        "callbacks",
-        "control_flow_loops",
-        "lists"
+        "strings"
       ]
     },
     {
-      "slug": "crypto-square",
-      "uuid": "4dc30879-a589-4dd3-b7b6-22261f9d1520",
+      "slug": "bracket-push",
+      "uuid": "4d456646-3a9b-4393-9558-6b30e5c1039c",
       "core": false,
-      "unlocked_by": "simple-cipher",
-      "difficulty": 9,
+      "unlocked_by": "pangram",
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-        "algorithms",
-        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "regular_expressions",
-        "sorting",
-        "text_formatting",
-        "transforming"
+        "exception_handling",
+        "parsing",
+        "strings"
       ]
     },
     {
-      "slug": "trinary",
-      "uuid": "1acf1d2d-a25e-4576-94de-0470abc872d9",
+      "slug": "high-scores",
+      "uuid": "19b41c4a-1466-5c19-b547-40284189fd18",
       "core": false,
-      "unlocked_by": null,
-      "difficulty": 4,
+      "unlocked_by": "pangram",
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       "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "integers",
-        "mathematics",
-        "regular_expressions",
-        "strings"
-      ],
-      "deprecated": true
+        "arrays"
+      ]
     },
     {
-      "slug": "sieve",
-      "uuid": "127287d1-ba44-4400-884a-6fe5f72e210f",
+      "slug": "grains",
+      "uuid": "d003975a-9045-4f03-9ad9-c15db584dc13",
       "core": false,
-      "unlocked_by": "prime-factors",
+      "unlocked_by": "space-age",
       "difficulty": 5,
       "topics": [
-        "control_flow_conditionals",
         "control_flow_loops",
-        "integers",
-        "math",
-        "recursion"
+        "integers"
       ]
     },
     {
-      "slug": "octal",
-      "uuid": "dec66f89-39d0-4857-9679-a035cf4259d7",
+      "slug": "perfect-numbers",
+      "uuid": "c6691fd2-e10d-47df-acbf-3adeac5a2f89",
       "core": false,
-      "unlocked_by": null,
-      "difficulty": 4,
+      "unlocked_by": "space-age",
+      "difficulty": 3,
       "topics": [
+        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
         "integers",
-        "mathematics",
-        "regular_expressions",
-        "strings"
-      ],
-      "deprecated": true
+        "math"
+      ]
     },
     {
       "slug": "luhn",
@@ -738,21 +645,6 @@
         "strings"
       ]
     },
-    {
-      "slug": "pig-latin",
-      "uuid": "16e25a38-7ce3-4ccd-b2f0-1550b837fe9b",
-      "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 4,
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-        "control_flow_conditionals",
-        "control_flow_loops",
-        "games",
-        "regular_expressions",
-        "strings",
-        "transforming"
-      ]
-    },
     {
       "slug": "pythagorean-triplet",
       "uuid": "394755a3-c743-4b85-b9b8-387907f4e32d",
@@ -767,19 +659,6 @@
         "math"
       ]
     },
-    {
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-      "uuid": "5178ae53-5364-46c9-bee3-70e6e8a8c2e3",
-      "core": false,
-      "unlocked_by": "pangram",
-      "difficulty": 3,
-      "topics": [
-        "control_flow_loops",
-        "exception_handling",
-        "strings",
-        "text_formatting"
-      ]
-    },
     {
       "slug": "difference-of-squares",
       "uuid": "7dfa878c-83a6-48ef-9170-b6633d51d601",
@@ -794,176 +673,170 @@
       ]
     },
     {
-      "slug": "proverb",
-      "uuid": "5626f5b6-207b-458b-92b6-eff2cadb240a",
+      "slug": "complex-numbers",
+      "uuid": "ea9a9a3e-ae6a-470d-8bb4-2afead507f24",
       "core": false,
-      "unlocked_by": "bob",
+      "unlocked_by": "space-age",
       "difficulty": 4,
       "topics": [
-        "arrays",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "optional_values",
-        "strings",
-        "text_formatting"
+        "math"
       ]
     },
     {
-      "slug": "flatten-array",
-      "uuid": "1a6c4a3b-d5db-4a5a-b123-66cf085defe6",
+      "slug": "forth",
+      "uuid": "e4035939-4375-4720-87ae-e613f925f013",
       "core": false,
-      "unlocked_by": "list-ops",
-      "difficulty": 5,
+      "unlocked_by": "matrix",
+      "difficulty": 8,
       "topics": [
-        "arrays",
-        "recursion"
+        "domain_specific_languages",
+        "parsing",
+        "stacks"
       ]
     },
     {
-      "slug": "hexadecimal",
-      "uuid": "8ed2c9fe-a13f-4313-abf9-125f351c85c9",
+      "slug": "saddle-points",
+      "uuid": "a01aa48c-65c4-4b1f-b3d9-3ec7da2ef754",
       "core": false,
-      "unlocked_by": null,
-      "difficulty": 4,
+      "unlocked_by": "matrix",
+      "difficulty": 6,
       "topics": [
         "control_flow_conditionals",
         "control_flow_loops",
+        "equality",
+        "exception_handling",
         "integers",
-        "mathematics",
-        "regular_expressions",
-        "strings"
-      ],
-      "deprecated": true
+        "matrices",
+        "optional_values",
+        "parsing"
+      ]
     },
     {
-      "slug": "largest-series-product",
-      "uuid": "1f84305d-ea76-4fe2-9858-3b53576d683d",
+      "slug": "ocr-numbers",
+      "uuid": "24c197ee-d492-4083-8615-629cb4b836b2",
       "core": false,
-      "unlocked_by": "pangram",
-      "difficulty": 7,
+      "unlocked_by": "matrix",
+      "difficulty": 5,
       "topics": [
         "control_flow_conditionals",
         "control_flow_loops",
+        "equality",
         "exception_handling",
         "integers",
-        "math",
-        "regular_expressions",
-        "strings"
+        "parsing",
+        "text_formatting"
       ]
     },
     {
-      "slug": "kindergarten-garden",
-      "uuid": "13444eff-005a-405e-9737-7b64d99c1a61",
+      "slug": "transpose",
+      "uuid": "9c140fb7-cc8b-411b-b613-a0e0081a9c3f",
       "core": false,
-      "unlocked_by": "wordy",
-      "difficulty": 7,
+      "unlocked_by": "matrix",
+      "difficulty": 1,
       "topics": [
         "arrays",
-        "control_flow_conditionals",
-        "control_flow_loops",
+        "lists",
+        "loops",
+        "matrices",
         "strings",
         "text_formatting"
       ]
     },
     {
-      "slug": "house",
-      "uuid": "a8b7187d-12eb-4efc-b966-87823654ccda",
+      "slug": "spiral-matrix",
+      "uuid": "c1abafcc-0d44-4fb5-afae-bff3ce2e1b39",
       "core": false,
-      "unlocked_by": "bob",
+      "unlocked_by": "matrix",
       "difficulty": 4,
       "topics": [
         "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "recursion",
-        "strings"
+        "data_structures",
+        "matrices"
       ]
     },
     {
-      "slug": "binary-search",
-      "uuid": "7c569e5d-bb00-44b8-8adc-34253790c19b",
+      "slug": "rectangles",
+      "uuid": "f8c6786e-bf93-4f35-b649-03f4e39bb094",
       "core": false,
-      "unlocked_by": "linked-list",
-      "difficulty": 7,
+      "unlocked_by": "matrix",
+      "difficulty": 4,
       "topics": [
-        "algorithms",
         "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "recursion"
+        "matrices",
+        "strings"
       ]
     },
     {
-      "slug": "binary-search-tree",
-      "uuid": "6c4b4e25-c115-4789-9058-d28ab6ca0d26",
+      "slug": "sublist",
+      "uuid": "4be85b5e-6b13-11e7-907b-a6006ad3dba0",
       "core": false,
       "unlocked_by": "linked-list",
-      "difficulty": 6,
+      "difficulty": 4,
       "topics": [
-        "algorithms",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "recursion"
+        "arrays",
+        "lists"
       ]
     },
     {
-      "slug": "robot-simulator",
-      "uuid": "5174bd15-eee2-4b53-b3ee-ca3a8c958a31",
+      "slug": "word-search",
+      "uuid": "0125f5a7-8883-4553-a6c1-45f19544af5e",
       "core": false,
-      "unlocked_by": "wordy",
-      "difficulty": 5,
+      "unlocked_by": "linked-list",
+      "difficulty": 8,
       "topics": [
+        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "exception_handling",
-        "games",
+        "equality",
+        "optional_values",
         "parsing",
-        "strings"
+        "text_formatting"
       ]
     },
     {
-      "slug": "nth-prime",
-      "uuid": "7ce09989-f202-4c3c-8b7e-72cef18808c3",
+      "slug": "circular-buffer",
+      "uuid": "bf0b1f95-3425-4345-8a12-3a80d49b49c9",
       "core": false,
-      "unlocked_by": "prime-factors",
-      "difficulty": 5,
+      "unlocked_by": "linked-list",
+      "difficulty": 8,
       "topics": [
-        "algorithms",
+        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
+        "data_structures",
         "exception_handling",
-        "integers",
-        "math"
+        "lists"
       ]
     },
     {
-      "slug": "palindrome-products",
-      "uuid": "f6799d10-0210-4c73-ac08-d5cac1a00ff3",
+      "slug": "binary-search",
+      "uuid": "7c569e5d-bb00-44b8-8adc-34253790c19b",
       "core": false,
-      "unlocked_by": "prime-factors",
+      "unlocked_by": "linked-list",
       "difficulty": 7,
       "topics": [
         "algorithms",
+        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "exception_handling",
-        "integers",
-        "math"
+        "recursion"
       ]
     },
     {
-      "slug": "say",
-      "uuid": "12989bb3-c593-4f68-bea4-e2c5b76bc3c0",
+      "slug": "binary-search-tree",
+      "uuid": "6c4b4e25-c115-4789-9058-d28ab6ca0d26",
       "core": false,
-      "unlocked_by": "bob",
+      "unlocked_by": "linked-list",
       "difficulty": 6,
       "topics": [
+        "algorithms",
         "control_flow_conditionals",
         "control_flow_loops",
-        "exception_handling",
-        "integers",
-        "strings",
-        "text_formatting"
+        "recursion"
       ]
     },
     {
@@ -984,127 +857,84 @@
       ]
     },
     {
-      "slug": "sum-of-multiples",
-      "uuid": "f7452f71-795b-40b6-847c-67ef4bb9db45",
-      "core": false,
-      "unlocked_by": "prime-factors",
-      "difficulty": 5,
-      "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "integers",
-        "lists",
-        "math"
-      ]
-    },
-    {
-      "slug": "queen-attack",
-      "uuid": "007a4cd4-7324-4512-8905-ead0c78146f7",
+      "slug": "simple-linked-list",
+      "uuid": "a1591026-2f02-45f9-b189-24b2359eb43f",
       "core": false,
-      "unlocked_by": null,
+      "unlocked_by": "linked-list",
       "difficulty": 8,
       "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "equality",
-        "exception_handling",
-        "optional_values",
-        "parsing",
-        "text_formatting"
+        "arrays",
+        "data_structures",
+        "lists"
       ]
     },
     {
-      "slug": "saddle-points",
-      "uuid": "a01aa48c-65c4-4b1f-b3d9-3ec7da2ef754",
+      "slug": "two-bucket",
+      "uuid": "0bc6b478-40a8-47ab-889b-c403b922f7e5",
       "core": false,
-      "unlocked_by": "matrix",
+      "unlocked_by": "grade-school",
       "difficulty": 6,
       "topics": [
+        "algorithms",
+        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "equality",
         "exception_handling",
-        "integers",
-        "matrices",
-        "optional_values",
+        "games",
         "parsing"
       ]
     },
     {
-      "slug": "ocr-numbers",
-      "uuid": "24c197ee-d492-4083-8615-629cb4b836b2",
+      "slug": "bowling",
+      "uuid": "dbf26ef1-62ff-4cb1-8ac7-09b022df3b2f",
       "core": false,
-      "unlocked_by": "matrix",
-      "difficulty": 5,
+      "unlocked_by": "grade-school",
+      "difficulty": 8,
       "topics": [
+        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "equality",
         "exception_handling",
-        "integers",
+        "games",
         "parsing",
         "text_formatting"
       ]
     },
     {
-      "slug": "meetup",
-      "uuid": "98617798-b49d-4d43-9f65-7131ee73d626",
+      "slug": "alphametics",
+      "uuid": "a602bd33-69fc-4b67-a3d3-95198853095e",
       "core": false,
-      "unlocked_by": "gigasecond",
+      "unlocked_by": "grade-school",
       "difficulty": 7,
       "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "dates",
-        "equality",
-        "exception_handling",
-        "time"
-      ]
-    },
-    {
-      "slug": "bracket-push",
-      "uuid": "4d456646-3a9b-4393-9558-6b30e5c1039c",
-      "core": false,
-      "unlocked_by": "pangram",
-      "difficulty": 3,
-      "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "exception_handling",
-        "parsing",
-        "strings"
+        "algorithms",
+        "games"
       ]
     },
     {
-      "slug": "two-bucket",
-      "uuid": "0bc6b478-40a8-47ab-889b-c403b922f7e5",
+      "slug": "connect",
+      "uuid": "2fa2c262-77ae-409b-bfd8-1d643faae772",
       "core": false,
       "unlocked_by": "grade-school",
-      "difficulty": 6,
+      "difficulty": 7,
       "topics": [
-        "algorithms",
         "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "exception_handling",
         "games",
+        "maps",
         "parsing"
       ]
     },
     {
-      "slug": "bowling",
-      "uuid": "dbf26ef1-62ff-4cb1-8ac7-09b022df3b2f",
+      "slug": "variable-length-quantity",
+      "uuid": "6be39d1f-f68d-4a52-bd72-85a38ffd509e",
       "core": false,
       "unlocked_by": "grade-school",
-      "difficulty": 8,
+      "difficulty": 5,
       "topics": [
-        "arrays",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "exception_handling",
-        "games",
-        "parsing",
-        "text_formatting"
+        "bitwise_operations",
+        "transforming"
       ]
     },
     {
@@ -1124,68 +954,47 @@
       ]
     },
     {
-      "slug": "all-your-base",
-      "uuid": "d2d3cd13-b06c-4c24-9964-fb1554f70dd4",
+      "slug": "rational-numbers",
+      "uuid": "d8da6cdd-3804-40b0-9821-0dd5765876ff",
       "core": false,
-      "unlocked_by": null,
+      "unlocked_by": "pascals-triangle",
       "difficulty": 5,
-      "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "exception_handling",
-        "integers",
-        "math",
-        "parsing"
-      ]
-    },
-    {
-      "slug": "minesweeper",
-      "uuid": "8bafe6c4-9154-4037-9070-7f57f91d495a",
-      "core": false,
-      "unlocked_by": null,
-      "difficulty": 7,
       "topics": [
         "algorithms",
-        "arrays",
-        "games"
+        "floating_point_numbers",
+        "math"
       ]
     },
     {
-      "slug": "alphametics",
-      "uuid": "a602bd33-69fc-4b67-a3d3-95198853095e",
+      "slug": "atbash-cipher",
+      "uuid": "a70e6027-eebe-43a1-84a6-763faa736169",
       "core": false,
-      "unlocked_by": "grade-school",
+      "unlocked_by": "simple-cipher",
       "difficulty": 7,
       "topics": [
         "algorithms",
-        "games"
-      ]
-    },
-    {
-      "slug": "simple-linked-list",
-      "uuid": "a1591026-2f02-45f9-b189-24b2359eb43f",
-      "core": false,
-      "unlocked_by": "linked-list",
-      "difficulty": 8,
-      "topics": [
         "arrays",
-        "data_structures",
-        "lists"
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "regular_expressions",
+        "text_formatting"
       ]
     },
     {
-      "slug": "connect",
-      "uuid": "2fa2c262-77ae-409b-bfd8-1d643faae772",
+      "slug": "crypto-square",
+      "uuid": "4dc30879-a589-4dd3-b7b6-22261f9d1520",
       "core": false,
-      "unlocked_by": "grade-school",
-      "difficulty": 7,
+      "unlocked_by": "simple-cipher",
+      "difficulty": 9,
       "topics": [
+        "algorithms",
         "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "games",
-        "maps",
-        "parsing"
+        "regular_expressions",
+        "sorting",
+        "text_formatting",
+        "transforming"
       ]
     },
     {
@@ -1204,180 +1013,371 @@
       ]
     },
     {
-      "slug": "change",
-      "uuid": "cfa5741c-9fe9-4cb5-a322-d77ba8145f4b",
+      "slug": "rotational-cipher",
+      "uuid": "34625b04-844e-41e3-b02b-3443b6b0b7cb",
       "core": false,
-      "unlocked_by": "prime-factors",
-      "difficulty": 8,
+      "unlocked_by": "simple-cipher",
+      "difficulty": 2,
       "topics": [
-        "algorithms",
-        "performance",
-        "searching"
+        "control_flow_conditionals",
+        "strings",
+        "text_formatting",
+        "transforming"
       ]
     },
     {
-      "slug": "twelve-days",
-      "uuid": "64de1776-d5c6-43fe-9abf-7e3aa08ae342",
+      "slug": "kindergarten-garden",
+      "uuid": "13444eff-005a-405e-9737-7b64d99c1a61",
       "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 4,
+      "unlocked_by": "wordy",
+      "difficulty": 7,
       "topics": [
+        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "pattern_recognition",
-        "polymorfism",
-        "regular_expressions",
-        "strings"
+        "strings",
+        "text_formatting"
       ]
     },
     {
-      "slug": "complex-numbers",
-      "uuid": "ea9a9a3e-ae6a-470d-8bb4-2afead507f24",
+      "slug": "robot-simulator",
+      "uuid": "5174bd15-eee2-4b53-b3ee-ca3a8c958a31",
       "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 4,
+      "unlocked_by": "wordy",
+      "difficulty": 5,
       "topics": [
-        "math"
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "exception_handling",
+        "games",
+        "parsing",
+        "strings"
       ]
     },
     {
-      "slug": "isbn-verifier",
-      "uuid": "b902c746-60d1-4645-a5bc-dafadec0ef32",
+      "slug": "strain",
+      "uuid": "8407f9d5-7a7e-40c8-aace-a6a8294ae5e9",
       "core": false,
-      "unlocked_by": "bob",
+      "unlocked_by": "list-ops",
       "difficulty": 4,
       "topics": [
+        "algorithms",
+        "arrays",
+        "callbacks",
         "control_flow_conditionals",
         "control_flow_loops",
-        "pattern_recognition",
-        "regular_expressions"
+        "filtering",
+        "lists"
       ]
     },
     {
-      "slug": "transpose",
-      "uuid": "9c140fb7-cc8b-411b-b613-a0e0081a9c3f",
+      "slug": "accumulate",
+      "uuid": "6ebe247c-3d11-48b7-8e6f-39f98359d233",
       "core": false,
-      "unlocked_by": "matrix",
-      "difficulty": 1,
+      "unlocked_by": "list-ops",
+      "difficulty": 5,
+      "topics": [
+        "algorithms",
+        "callbacks",
+        "control_flow_loops",
+        "lists"
+      ]
+    },
+    {
+      "slug": "flatten-array",
+      "uuid": "1a6c4a3b-d5db-4a5a-b123-66cf085defe6",
+      "core": false,
+      "unlocked_by": "list-ops",
+      "difficulty": 5,
       "topics": [
         "arrays",
-        "lists",
-        "loops",
-        "matrices",
+        "recursion"
+      ]
+    },
+    {
+      "slug": "zipper",
+      "uuid": "fd1575f3-3087-4cfa-8a26-168fba6d0606",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 8,
+      "topics": [
+        "recursion",
+        "searching",
+        "trees"
+      ]
+    },
+    {
+      "slug": "point-mutations",
+      "uuid": "6d43709b-3809-4a6a-ab41-2a5ab841b5fb",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 0,
+      "topics": null,
+      "deprecated": true
+    },
+    {
+      "slug": "darts",
+      "uuid": "6c64649b-ea81-4118-9e74-a0a55018ffbc",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 3,
+      "topics": null
+    },
+    {
+      "slug": "binary",
+      "uuid": "0ba4d3b9-2519-49ac-bd93-f960aca6c11f",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 4,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "exception_handling",
+        "integers",
+        "mathematics",
+        "regular_expressions",
+        "strings"
+      ],
+      "deprecated": true
+    },
+    {
+      "slug": "prime-factors",
+      "uuid": "f43cdddf-eea8-4c4a-8359-c69e20ff9661",
+      "core": true,
+      "unlocked_by": null,
+      "difficulty": 4,
+      "topics": [
+        "algorithms",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "integers",
+        "math"
+      ]
+    },
+    {
+      "slug": "run-length-encoding",
+      "uuid": "6ac4ad5f-a64a-4646-91c5-169d53f289f9",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 2,
+      "topics": [
+        "control_flow_conditionals",
+        "exception_handling",
+        "parsing",
+        "pattern_recognition",
+        "regular_expressions",
         "strings",
         "text_formatting"
       ]
     },
     {
-      "slug": "protein-translation",
-      "uuid": "775ae0ec-8db7-4568-a188-963931cf5ee1",
+      "slug": "roman-numerals",
+      "uuid": "2fc4f834-a51c-42b8-a4d9-5263229e7648",
       "core": false,
       "unlocked_by": null,
-      "difficulty": 1,
+      "difficulty": 3,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "pattern_recognition",
+        "transforming"
+      ]
+    },
+    {
+      "slug": "react",
+      "uuid": "303c6969-9446-41aa-871a-11223a43e810",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 8,
       "topics": [
         "algorithms",
+        "events",
+        "reactive_programming"
+      ]
+    },
+    {
+      "slug": "trinary",
+      "uuid": "1acf1d2d-a25e-4576-94de-0470abc872d9",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 4,
+      "topics": [
         "control_flow_conditionals",
         "control_flow_loops",
+        "integers",
+        "mathematics",
+        "regular_expressions",
         "strings"
+      ],
+      "deprecated": true
+    },
+    {
+      "slug": "sieve",
+      "uuid": "127287d1-ba44-4400-884a-6fe5f72e210f",
+      "core": false,
+      "unlocked_by": "prime-factors",
+      "difficulty": 5,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "integers",
+        "math",
+        "recursion"
       ]
     },
     {
-      "slug": "spiral-matrix",
-      "uuid": "c1abafcc-0d44-4fb5-afae-bff3ce2e1b39",
+      "slug": "octal",
+      "uuid": "dec66f89-39d0-4857-9679-a035cf4259d7",
       "core": false,
-      "unlocked_by": "matrix",
+      "unlocked_by": null,
       "difficulty": 4,
       "topics": [
-        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "data_structures",
-        "matrices"
-      ]
+        "integers",
+        "mathematics",
+        "regular_expressions",
+        "strings"
+      ],
+      "deprecated": true
     },
     {
-      "slug": "rectangles",
-      "uuid": "f8c6786e-bf93-4f35-b649-03f4e39bb094",
+      "slug": "hexadecimal",
+      "uuid": "8ed2c9fe-a13f-4313-abf9-125f351c85c9",
       "core": false,
-      "unlocked_by": "matrix",
+      "unlocked_by": null,
       "difficulty": 4,
       "topics": [
-        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "matrices",
+        "integers",
+        "mathematics",
+        "regular_expressions",
         "strings"
+      ],
+      "deprecated": true
+    },
+    {
+      "slug": "nth-prime",
+      "uuid": "7ce09989-f202-4c3c-8b7e-72cef18808c3",
+      "core": false,
+      "unlocked_by": "prime-factors",
+      "difficulty": 5,
+      "topics": [
+        "algorithms",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "exception_handling",
+        "integers",
+        "math"
       ]
     },
     {
-      "slug": "rotational-cipher",
-      "uuid": "34625b04-844e-41e3-b02b-3443b6b0b7cb",
+      "slug": "palindrome-products",
+      "uuid": "f6799d10-0210-4c73-ac08-d5cac1a00ff3",
       "core": false,
-      "unlocked_by": "simple-cipher",
-      "difficulty": 2,
+      "unlocked_by": "prime-factors",
+      "difficulty": 7,
       "topics": [
+        "algorithms",
         "control_flow_conditionals",
-        "strings",
-        "text_formatting",
-        "transforming"
+        "control_flow_loops",
+        "exception_handling",
+        "integers",
+        "math"
       ]
     },
     {
-      "slug": "nucleotide-count",
-      "uuid": "be6f3ab3-1593-4c2d-8a35-5f39c1d5c91f",
+      "slug": "sum-of-multiples",
+      "uuid": "f7452f71-795b-40b6-847c-67ef4bb9db45",
       "core": false,
-      "unlocked_by": "rna-transcription",
-      "difficulty": 4,
+      "unlocked_by": "prime-factors",
+      "difficulty": 5,
       "topics": [
-        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "strings",
+        "integers",
+        "lists",
+        "math"
+      ]
+    },
+    {
+      "slug": "queen-attack",
+      "uuid": "007a4cd4-7324-4512-8905-ead0c78146f7",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 8,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "equality",
+        "exception_handling",
+        "optional_values",
+        "parsing",
         "text_formatting"
       ]
     },
     {
-      "slug": "armstrong-numbers",
-      "uuid": "b28c34f4-f7af-47db-95c6-f920e020bbba",
+      "slug": "all-your-base",
+      "uuid": "d2d3cd13-b06c-4c24-9964-fb1554f70dd4",
       "core": false,
       "unlocked_by": null,
-      "difficulty": 2,
+      "difficulty": 5,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "exception_handling",
+        "integers",
+        "math",
+        "parsing"
+      ]
+    },
+    {
+      "slug": "minesweeper",
+      "uuid": "8bafe6c4-9154-4037-9070-7f57f91d495a",
+      "core": false,
+      "unlocked_by": null,
+      "difficulty": 7,
       "topics": [
         "algorithms",
-        "math"
+        "arrays",
+        "games"
       ]
     },
     {
-      "slug": "rational-numbers",
-      "uuid": "d8da6cdd-3804-40b0-9821-0dd5765876ff",
+      "slug": "change",
+      "uuid": "cfa5741c-9fe9-4cb5-a322-d77ba8145f4b",
       "core": false,
-      "unlocked_by": "pascals-triangle",
-      "difficulty": 5,
+      "unlocked_by": "prime-factors",
+      "difficulty": 8,
       "topics": [
         "algorithms",
-        "floating_point_numbers",
-        "math"
+        "performance",
+        "searching"
       ]
     },
     {
-      "slug": "variable-length-quantity",
-      "uuid": "6be39d1f-f68d-4a52-bd72-85a38ffd509e",
+      "slug": "protein-translation",
+      "uuid": "775ae0ec-8db7-4568-a188-963931cf5ee1",
       "core": false,
-      "unlocked_by": "grade-school",
-      "difficulty": 5,
+      "unlocked_by": null,
+      "difficulty": 1,
       "topics": [
-        "bitwise_operations",
-        "transforming"
+        "algorithms",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "strings"
       ]
     },
     {
-      "slug": "high-scores",
-      "uuid": "19b41c4a-1466-5c19-b547-40284189fd18",
+      "slug": "armstrong-numbers",
+      "uuid": "b28c34f4-f7af-47db-95c6-f920e020bbba",
       "core": false,
-      "unlocked_by": "pangram",
+      "unlocked_by": null,
       "difficulty": 2,
       "topics": [
-        "arrays"
+        "algorithms",
+        "math"
       ]
     }
   ]

From a89762fb02fb9aa1fd3257172896088eafe43be0 Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Mon, 21 Jan 2019 21:18:01 +0100
Subject: [PATCH 02/11] Demote prime-factors from core to side exercise

Prime factors is a mathy exercise and as part of round one, mathy exercises should be demoted to side exercise.
---
 config.json | 28 ++++++++++++++--------------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/config.json b/config.json
index 42ca9fef08..82eb8e8bba 100644
--- a/config.json
+++ b/config.json
@@ -682,6 +682,20 @@
         "math"
       ]
     },
+    {
+      "slug": "prime-factors",
+      "uuid": "f43cdddf-eea8-4c4a-8359-c69e20ff9661",
+      "core": false,
+      "unlocked_by": "space-age",
+      "difficulty": 4,
+      "topics": [
+        "algorithms",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "integers",
+        "math"
+      ]
+    },
     {
       "slug": "forth",
       "uuid": "e4035939-4375-4720-87ae-e613f925f013",
@@ -1140,20 +1154,6 @@
       ],
       "deprecated": true
     },
-    {
-      "slug": "prime-factors",
-      "uuid": "f43cdddf-eea8-4c4a-8359-c69e20ff9661",
-      "core": true,
-      "unlocked_by": null,
-      "difficulty": 4,
-      "topics": [
-        "algorithms",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "integers",
-        "math"
-      ]
-    },
     {
       "slug": "run-length-encoding",
       "uuid": "6ac4ad5f-a64a-4646-91c5-169d53f289f9",

From b3058e1e39eb803491a0105a584c320ede507c75 Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Mon, 21 Jan 2019 21:20:35 +0100
Subject: [PATCH 03/11] Update simple-cipher difficulty

This is an extensive exercise with four parts. Even though it's not a particularly difficult one to understand, it's actually difficult for beginners (< 4) to implement. Making this number higher makes sure it's no longer listed as easy.
---
 config.json | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/config.json b/config.json
index 82eb8e8bba..b2b35841cf 100644
--- a/config.json
+++ b/config.json
@@ -169,7 +169,7 @@
       "uuid": "62d60b42-93bc-4de9-90d1-1ca18a847812",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 1,
+      "difficulty": 6,
       "topics": [
         "algorithms",
         "control_flow_conditionals",

From c608c75c674b79c8a021fa44bafe25bf722c705b Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Mon, 21 Jan 2019 21:49:22 +0100
Subject: [PATCH 04/11] Add helper binaries for printing the tree of exercises
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

This generates the output (as of this commit):

Core (matches config.json) of this track:
- hello-world (1)
- leap (1)
- gigasecond (2)
- rna-transcription (1)
- bob (2)
- pangram (2)
- space-age (3)
- matrix (4)
- linked-list (5)
- grade-school (6)
- robot-name (6)
- pascals-triangle (5)
- simple-cipher (6)
- wordy (7)
- secret-handshake (6)
- list-ops (8)

core
----
├─ hello-world
│  ├─ two-fer (1)
│
├─ leap
│  ├─ reverse-string (2)
│  ├─ triangle (3)
│  ├─ collatz-conjecture (3)
│
├─ gigasecond
│  ├─ clock (5)
│  ├─ meetup (7)
│
├─ rna-transcription
│  ├─ hamming (2)
│  ├─ etl (2)
│  ├─ scrabble-score (5)
│  ├─ raindrops (2)
│  ├─ allergies (6)
│  ├─ nucleotide-count (4)
│
├─ bob
│  ├─ beer-song (5)
│  ├─ food-chain (4)
│  ├─ pig-latin (4)
│  ├─ proverb (4)
│  ├─ house (4)
│  ├─ twelve-days (4)
│  ├─ say (6)
│  ├─ isbn-verifier (4)
│
├─ pangram
│  ├─ isogram (2)
│  ├─ phone-number (3)
│  ├─ anagram (1)
│  ├─ word-count (1)
│  ├─ acronym (2)
│  ├─ series (3)
│  ├─ largest-series-product (7)
│  ├─ bracket-push (3)
│  ├─ high-scores (2)
│
├─ space-age
│  ├─ grains (5)
│  ├─ perfect-numbers (3)
│  ├─ luhn (4)
│  ├─ pythagorean-triplet (5)
│  ├─ difference-of-squares (3)
│  ├─ complex-numbers (4)
│  ├─ prime-factors (4)
│
├─ matrix
│  ├─ forth (8)
│  ├─ saddle-points (6)
│  ├─ ocr-numbers (5)
│  ├─ transpose (1)
│  ├─ spiral-matrix (4)
│  ├─ rectangles (4)
│
├─ linked-list
│  ├─ sublist (4)
│  ├─ word-search (8)
│  ├─ circular-buffer (8)
│  ├─ binary-search (7)
│  ├─ binary-search-tree (6)
│  ├─ custom-set (6)
│  ├─ simple-linked-list (8)
│
├─ grade-school
│  ├─ two-bucket (6)
│  ├─ bowling (8)
│  ├─ alphametics (7)
│  ├─ connect (7)
│  ├─ variable-length-quantity (5)
│
├─ pascals-triangle
│  ├─ diamond (5)
│  ├─ rational-numbers (5)
│
├─ simple-cipher
│  ├─ atbash-cipher (7)
│  ├─ crypto-square (9)
│  ├─ diffie-hellman (3)
│  ├─ rotational-cipher (2)
│
├─ wordy
│  ├─ kindergarten-garden (7)
│  ├─ robot-simulator (5)
│
├─ list-ops
│  ├─ strain (4)
│  ├─ accumulate (5)
│  ├─ flatten-array (5)
│
├─ prime-factors
│  ├─ sieve (5)
│  ├─ nth-prime (5)
│  ├─ palindrome-products (7)
│  ├─ sum-of-multiples (5)
│  ├─ change (8)
│
bonus
----
- zipper (8)
- point-mutations (0)
- darts (3)
- binary (4)
- run-length-encoding (2)
- roman-numerals (3)
- react (8)
- trinary (4)
- octal (4)
- hexadecimal (4)
- queen-attack (8)
- all-your-base (5)
- minesweeper (7)
- protein-translation (1)
- armstrong-numbers (2)
---
 bin/generate-config-tree | 34 ++++++++++++++++++++++++++++++++++
 bin/print-config-tree    | 33 +++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 bin/generate-config-tree
 create mode 100644 bin/print-config-tree

diff --git a/bin/generate-config-tree b/bin/generate-config-tree
new file mode 100644
index 0000000000..28512e2462
--- /dev/null
+++ b/bin/generate-config-tree
@@ -0,0 +1,34 @@
+#!/usr/bin/env node
+
+const { exercises } = require('../config.json')
+const TAG_CORE = '__core'
+const TAG_BONUS = '__bonus'
+
+// node inter-opt exports
+exports.TAG_CORE = TAG_CORE
+exports.TAG_BONUS = TAG_BONUS
+
+exports.tree = exercises.reduce((result, exercise) => {
+    const tag = exercise.slug
+    const item = {
+        slug: tag,
+        difficulty: exercise.difficulty
+    }
+
+    if (exercise.core) {
+        const current = result[TAG_CORE] || []
+
+        if (result[tag]) {
+            console.warn(`${tag} is not ordered correctly in config.json`)
+        }
+
+        return {
+            ...result,
+            __core: current.concat([item])
+        }
+    }
+
+    const parent = exercise.unlocked_by || TAG_BONUS
+    const current = result[parent] || []
+    return { ...result, [parent]: current.concat([item]) }
+}, {})
diff --git a/bin/print-config-tree b/bin/print-config-tree
new file mode 100644
index 0000000000..6d537e2a42
--- /dev/null
+++ b/bin/print-config-tree
@@ -0,0 +1,33 @@
+#!/usr/bin/env node
+
+const actions = require('./generate-config-tree')
+
+const { tree, TAG_BONUS, TAG_CORE } = actions
+const { [TAG_BONUS]: __bonus, [TAG_CORE]: __core, ...track } = tree
+
+function printLn(line) {
+    process.stdout.write(`${line}\n`)
+}
+
+function printList(items) {
+    items.forEach(item => {
+        printLn(`- ${item.slug} (${item.difficulty})`)
+    })
+}
+
+printLn('Core (matches config.json) of this track:')
+printList(__core)
+printLn('\n')
+printLn('core')
+printLn('----')
+Object.keys(track).forEach(slug => {
+    printLn(`├─ ${slug}`)
+    track[slug].forEach(side => {
+        printLn(`│  ├─ ${side.slug} (${side.difficulty})`)
+    })
+    printLn('│')
+})
+
+printLn('bonus')
+printLn('----')
+printList(__bonus)

From dfd12e5b43a9135798b32f51084a3293732125f6 Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Mon, 21 Jan 2019 21:54:44 +0100
Subject: [PATCH 05/11] Fix the script to include core exercises that don't
 unlock anything

---
 bin/generate-config-tree | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/bin/generate-config-tree b/bin/generate-config-tree
index 28512e2462..9a08db2e3a 100644
--- a/bin/generate-config-tree
+++ b/bin/generate-config-tree
@@ -12,7 +12,7 @@ exports.tree = exercises.reduce((result, exercise) => {
     const tag = exercise.slug
     const item = {
         slug: tag,
-        difficulty: exercise.difficulty
+        difficulty: exercise.difficulty,
     }
 
     if (exercise.core) {
@@ -24,7 +24,8 @@ exports.tree = exercises.reduce((result, exercise) => {
 
         return {
             ...result,
-            __core: current.concat([item])
+            __core: current.concat([item]),
+            [tag]: result[tag] || []
         }
     }
 

From d07fc9f75be129a3ec263a2764bc799bafa0e008 Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Mon, 21 Jan 2019 21:54:59 +0100
Subject: [PATCH 06/11] nit: junction for the last item in the list

---
 bin/print-config-tree | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/bin/print-config-tree b/bin/print-config-tree
index 6d537e2a42..337c2c09fd 100644
--- a/bin/print-config-tree
+++ b/bin/print-config-tree
@@ -22,8 +22,9 @@ printLn('core')
 printLn('----')
 Object.keys(track).forEach(slug => {
     printLn(`├─ ${slug}`)
-    track[slug].forEach(side => {
-        printLn(`│  ├─ ${side.slug} (${side.difficulty})`)
+    track[slug].forEach((side, index, self) => {
+        junction = index === self.length - 1 ? '└─' : '├─'
+        printLn(`│  ${junction} ${side.slug} (${side.difficulty})`)
     })
     printLn('│')
 })

From 732a91799f0a20aa261e1073f5e5044f378940f7 Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Mon, 21 Jan 2019 22:33:52 +0100
Subject: [PATCH 07/11] Re-assign prime-factors unlocks
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Assigning them one up, and give two exercises to "secret-handshake" which had none:

Core (matches config.json) of this track:
- hello-world (1)
- leap (1)
- gigasecond (2)
- rna-transcription (1)
- bob (2)
- pangram (2)
- space-age (3)
- matrix (4)
- linked-list (5)
- grade-school (6)
- robot-name (6)
- pascals-triangle (5)
- simple-cipher (6)
- wordy (7)
- secret-handshake (6)
- list-ops (8)

core
----
├─ hello-world
│  └─ two-fer (1)
│
├─ leap
│  ├─ reverse-string (2)
│  ├─ triangle (3)
│  └─ collatz-conjecture (3)
│
├─ gigasecond
│  ├─ clock (5)
│  └─ meetup (7)
│
├─ rna-transcription
│  ├─ hamming (2)
│  ├─ etl (2)
│  ├─ scrabble-score (5)
│  ├─ raindrops (2)
│  ├─ allergies (6)
│  └─ nucleotide-count (4)
│
├─ bob
│  ├─ beer-song (5)
│  ├─ food-chain (4)
│  ├─ pig-latin (4)
│  ├─ proverb (4)
│  ├─ house (4)
│  ├─ twelve-days (4)
│  ├─ say (6)
│  └─ isbn-verifier (4)
│
├─ pangram
│  ├─ isogram (2)
│  ├─ phone-number (3)
│  ├─ anagram (1)
│  ├─ word-count (1)
│  ├─ acronym (2)
│  ├─ series (3)
│  ├─ largest-series-product (7)
│  ├─ bracket-push (3)
│  └─ high-scores (2)
│
├─ space-age
│  ├─ grains (5)
│  ├─ perfect-numbers (3)
│  ├─ luhn (4)
│  ├─ pythagorean-triplet (5)
│  ├─ difference-of-squares (3)
│  ├─ complex-numbers (4)
│  ├─ prime-factors (4)
│  ├─ sieve (5)
│  ├─ nth-prime (5)
│  └─ palindrome-products (7)
│
├─ matrix
│  ├─ forth (8)
│  ├─ saddle-points (6)
│  ├─ ocr-numbers (5)
│  ├─ transpose (1)
│  ├─ spiral-matrix (4)
│  └─ rectangles (4)
│
├─ linked-list
│  ├─ sublist (4)
│  ├─ word-search (8)
│  ├─ circular-buffer (8)
│  ├─ binary-search (7)
│  ├─ binary-search-tree (6)
│  ├─ custom-set (6)
│  └─ simple-linked-list (8)
│
├─ grade-school
│  ├─ two-bucket (6)
│  ├─ bowling (8)
│  ├─ alphametics (7)
│  ├─ connect (7)
│  └─ variable-length-quantity (5)
│
├─ robot-name
│
├─ pascals-triangle
│  ├─ diamond (5)
│  └─ rational-numbers (5)
│
├─ simple-cipher
│  ├─ atbash-cipher (7)
│  ├─ crypto-square (9)
│  ├─ diffie-hellman (3)
│  └─ rotational-cipher (2)
│
├─ wordy
│  ├─ kindergarten-garden (7)
│  └─ robot-simulator (5)
│
├─ secret-handshake
│  ├─ sum-of-multiples (5)
│  └─ change (8)
│
├─ list-ops
│  ├─ strain (4)
│  ├─ accumulate (5)
│  └─ flatten-array (5)
│
bonus
----
- zipper (8)
- point-mutations (0)
- darts (3)
- binary (4)
- run-length-encoding (2)
- roman-numerals (3)
- react (8)
- trinary (4)
- octal (4)
- hexadecimal (4)
- queen-attack (8)
- all-your-base (5)
- minesweeper (7)
- protein-translation (1)
- armstrong-numbers (2)
---
 config.json | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/config.json b/config.json
index b2b35841cf..b59f31059f 100644
--- a/config.json
+++ b/config.json
@@ -1215,7 +1215,7 @@
       "slug": "sieve",
       "uuid": "127287d1-ba44-4400-884a-6fe5f72e210f",
       "core": false,
-      "unlocked_by": "prime-factors",
+      "unlocked_by": "space-age",
       "difficulty": 5,
       "topics": [
         "control_flow_conditionals",
@@ -1261,7 +1261,7 @@
       "slug": "nth-prime",
       "uuid": "7ce09989-f202-4c3c-8b7e-72cef18808c3",
       "core": false,
-      "unlocked_by": "prime-factors",
+      "unlocked_by": "space-age",
       "difficulty": 5,
       "topics": [
         "algorithms",
@@ -1276,7 +1276,7 @@
       "slug": "palindrome-products",
       "uuid": "f6799d10-0210-4c73-ac08-d5cac1a00ff3",
       "core": false,
-      "unlocked_by": "prime-factors",
+      "unlocked_by": "space-age",
       "difficulty": 7,
       "topics": [
         "algorithms",
@@ -1291,7 +1291,7 @@
       "slug": "sum-of-multiples",
       "uuid": "f7452f71-795b-40b6-847c-67ef4bb9db45",
       "core": false,
-      "unlocked_by": "prime-factors",
+      "unlocked_by": "secret-handshake",
       "difficulty": 5,
       "topics": [
         "control_flow_conditionals",
@@ -1348,7 +1348,7 @@
       "slug": "change",
       "uuid": "cfa5741c-9fe9-4cb5-a322-d77ba8145f4b",
       "core": false,
-      "unlocked_by": "prime-factors",
+      "unlocked_by": "secret-handshake",
       "difficulty": 8,
       "topics": [
         "algorithms",

From 7b076e2227bfc694eae15eea2effaab64d17ad46 Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Thu, 24 Jan 2019 16:05:12 +0100
Subject: [PATCH 08/11] Reorder based on mentor-notes, examples and
 conversation

- Moving bob down
- Moving list-ops up
- Moving space-age up (because of new exercise implementation)
---
 .gitattributes |  1 +
 config.json    | 88 +++++++++++++++++++++++++-------------------------
 2 files changed, 45 insertions(+), 44 deletions(-)
 create mode 100644 .gitattributes

diff --git a/.gitattributes b/.gitattributes
new file mode 100644
index 0000000000..cbdcbbc258
--- /dev/null
+++ b/.gitattributes
@@ -0,0 +1 @@
+*.js text eol=lf
diff --git a/config.json b/config.json
index b59f31059f..0780885db1 100644
--- a/config.json
+++ b/config.json
@@ -52,18 +52,14 @@
       ]
     },
     {
-      "slug": "bob",
-      "uuid": "a5bf36f0-5d3c-41d4-8d54-e37e484e59cd",
+      "slug": "space-age",
+      "uuid": "d9d757ed-ebe6-4d4a-aa73-f6834221cd54",
       "core": true,
       "unlocked_by": null,
       "difficulty": 2,
       "topics": [
-        "control_flow_conditionals",
-        "pattern_recognition",
-        "polymorfism",
-        "regular_expressions",
-        "strings",
-        "unicode"
+        "classes",
+        "floating_point_numbers"
       ]
     },
     {
@@ -83,28 +79,46 @@
       ]
     },
     {
-      "slug": "space-age",
-      "uuid": "d9d757ed-ebe6-4d4a-aa73-f6834221cd54",
+      "slug": "matrix",
+      "uuid": "dd0b5e67-81f6-437e-8334-2ec0dfeb862a",
       "core": true,
       "unlocked_by": null,
       "difficulty": 3,
       "topics": [
-        "classes",
-        "floating_point_numbers"
+        "arrays",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "data_structures",
+        "matrices",
+        "text_formatting"
       ]
     },
     {
-      "slug": "matrix",
-      "uuid": "dd0b5e67-81f6-437e-8334-2ec0dfeb862a",
+      "slug": "bob",
+      "uuid": "a5bf36f0-5d3c-41d4-8d54-e37e484e59cd",
+      "core": true,
+      "unlocked_by": null,
+      "difficulty": 4,
+      "topics": [
+        "control_flow_conditionals",
+        "pattern_recognition",
+        "polymorfism",
+        "regular_expressions",
+        "strings",
+        "unicode"
+      ]
+    },
+    {
+      "slug": "pascals-triangle",
+      "uuid": "99493160-4673-402f-acda-62db5378148d",
       "core": true,
       "unlocked_by": null,
       "difficulty": 4,
       "topics": [
-        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "data_structures",
-        "matrices",
+        "math",
+        "strings",
         "text_formatting"
       ]
     },
@@ -137,31 +151,30 @@
       ]
     },
     {
-      "slug": "robot-name",
-      "uuid": "03f4dfea-e6db-4754-b2c8-ca06c8b81ef1",
+      "slug": "list-ops",
+      "uuid": "7d9db056-5398-41b6-af3b-9707f5eb0dbc",
       "core": true,
       "unlocked_by": null,
       "difficulty": 6,
       "topics": [
-        "control_flow_conditionals",
-        "exception_handling",
-        "randomness",
-        "regular_expressions",
-        "sets"
+        "control_flow_loops",
+        "data_structures",
+        "lists",
+        "recursion"
       ]
     },
     {
-      "slug": "pascals-triangle",
-      "uuid": "99493160-4673-402f-acda-62db5378148d",
+      "slug": "robot-name",
+      "uuid": "03f4dfea-e6db-4754-b2c8-ca06c8b81ef1",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 5,
+      "difficulty": 6,
       "topics": [
         "control_flow_conditionals",
-        "control_flow_loops",
-        "math",
-        "strings",
-        "text_formatting"
+        "exception_handling",
+        "randomness",
+        "regular_expressions",
+        "sets"
       ]
     },
     {
@@ -211,19 +224,6 @@
         "games"
       ]
     },
-    {
-      "slug": "list-ops",
-      "uuid": "7d9db056-5398-41b6-af3b-9707f5eb0dbc",
-      "core": true,
-      "unlocked_by": null,
-      "difficulty": 8,
-      "topics": [
-        "control_flow_loops",
-        "data_structures",
-        "lists",
-        "recursion"
-      ]
-    },
     {
       "slug": "two-fer",
       "uuid": "7f49e997-4435-4f34-a020-bddc92c838ed",

From 858bd058e09c160bbe20242bec8353ead216f7c5 Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Thu, 24 Jan 2019 16:05:30 +0100
Subject: [PATCH 09/11] Remove .gitattributes

---
 .gitattributes | 1 -
 1 file changed, 1 deletion(-)
 delete mode 100644 .gitattributes

diff --git a/.gitattributes b/.gitattributes
deleted file mode 100644
index cbdcbbc258..0000000000
--- a/.gitattributes
+++ /dev/null
@@ -1 +0,0 @@
-*.js text eol=lf

From 632dd297132e58c699535d6480c6d44c182f9827 Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Thu, 24 Jan 2019 16:05:37 +0100
Subject: [PATCH 10/11] Tweak difficulties

---
 config.json | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/config.json b/config.json
index 0780885db1..f48a7fc1a8 100644
--- a/config.json
+++ b/config.json
@@ -35,7 +35,7 @@
       "uuid": "fd7b62d4-266b-4e84-a526-bf3d47901216",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 2,
+      "difficulty": 1,
       "topics": [
         "time"
       ]
@@ -45,7 +45,7 @@
       "uuid": "342974d6-9083-4754-a6c5-ed1e19e40ec5",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 1,
+      "difficulty": 2,
       "topics": [
         "strings",
         "transforming"
@@ -143,7 +143,7 @@
       "uuid": "64637322-33bc-401f-8cec-1f9810a41f75",
       "core": true,
       "unlocked_by": null,
-      "difficulty": 6,
+      "difficulty": 5,
       "topics": [
         "arrays",
         "maps",

From 98dacaf001030a73a71563653bdf7254aea26b0f Mon Sep 17 00:00:00 2001
From: Derk-Jan Karrenbeld <derk-jan+github@karrenbeld.info>
Date: Thu, 24 Jan 2019 16:29:35 +0100
Subject: [PATCH 11/11] Update config.json orderering to match track

---
 config.json | 715 ++++++++++++++++++++++++++--------------------------
 1 file changed, 359 insertions(+), 356 deletions(-)

diff --git a/config.json b/config.json
index f48a7fc1a8..8da5f324f9 100644
--- a/config.json
+++ b/config.json
@@ -384,114 +384,123 @@
         "text_formatting"
       ]
     },
+
     {
-      "slug": "beer-song",
-      "uuid": "6573f168-d8fc-4ccf-a864-1a61f432fae1",
+      "slug": "grains",
+      "uuid": "d003975a-9045-4f03-9ad9-c15db584dc13",
       "core": false,
-      "unlocked_by": "bob",
+      "unlocked_by": "space-age",
       "difficulty": 5,
       "topics": [
-        "control_flow_conditionals",
         "control_flow_loops",
-        "strings"
+        "integers"
       ]
     },
     {
-      "slug": "food-chain",
-      "uuid": "62672dc7-e827-4c2e-a282-d6df45b60bbd",
+      "slug": "word-count",
+      "uuid": "0073ff9a-cd6a-43cf-b8bf-4d5d8117b81b",
       "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 4,
+      "unlocked_by": "space-age",
+      "difficulty": 1,
       "topics": [
-        "algorithms",
-        "text_formatting"
+        "control_flow_loops",
+        "lists",
+        "regular_expressions",
+        "strings",
+        "unicode"
       ]
     },
     {
-      "slug": "pig-latin",
-      "uuid": "16e25a38-7ce3-4ccd-b2f0-1550b837fe9b",
+      "slug": "perfect-numbers",
+      "uuid": "c6691fd2-e10d-47df-acbf-3adeac5a2f89",
       "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 4,
+      "unlocked_by": "space-age",
+      "difficulty": 3,
       "topics": [
+        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "games",
-        "regular_expressions",
-        "strings",
-        "transforming"
+        "integers",
+        "math"
       ]
     },
     {
-      "slug": "proverb",
-      "uuid": "5626f5b6-207b-458b-92b6-eff2cadb240a",
+      "slug": "luhn",
+      "uuid": "28872cc9-f1ef-487f-9a79-6bf7983148bf",
       "core": false,
-      "unlocked_by": "bob",
+      "unlocked_by": "space-age",
       "difficulty": 4,
       "topics": [
-        "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
-        "optional_values",
-        "strings",
-        "text_formatting"
+        "integers",
+        "strings"
       ]
     },
     {
-      "slug": "house",
-      "uuid": "a8b7187d-12eb-4efc-b966-87823654ccda",
+      "slug": "pythagorean-triplet",
+      "uuid": "394755a3-c743-4b85-b9b8-387907f4e32d",
       "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 4,
+      "unlocked_by": "space-age",
+      "difficulty": 5,
       "topics": [
-        "arrays",
+        "algorithms",
         "control_flow_conditionals",
         "control_flow_loops",
-        "recursion",
-        "strings"
+        "integers",
+        "math"
       ]
     },
     {
-      "slug": "twelve-days",
-      "uuid": "64de1776-d5c6-43fe-9abf-7e3aa08ae342",
+      "slug": "difference-of-squares",
+      "uuid": "7dfa878c-83a6-48ef-9170-b6633d51d601",
       "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 4,
+      "unlocked_by": "space-age",
+      "difficulty": 3,
       "topics": [
-        "control_flow_conditionals",
+        "algorithms",
         "control_flow_loops",
-        "pattern_recognition",
-        "polymorfism",
-        "regular_expressions",
-        "strings"
+        "integers",
+        "math"
       ]
     },
     {
-      "slug": "say",
-      "uuid": "12989bb3-c593-4f68-bea4-e2c5b76bc3c0",
+      "slug": "complex-numbers",
+      "uuid": "ea9a9a3e-ae6a-470d-8bb4-2afead507f24",
       "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 6,
+      "unlocked_by": "space-age",
+      "difficulty": 4,
+      "topics": [
+        "math"
+      ]
+    },
+    {
+      "slug": "prime-factors",
+      "uuid": "f43cdddf-eea8-4c4a-8359-c69e20ff9661",
+      "core": false,
+      "unlocked_by": "space-age",
+      "difficulty": 4,
       "topics": [
+        "algorithms",
         "control_flow_conditionals",
         "control_flow_loops",
-        "exception_handling",
         "integers",
-        "strings",
-        "text_formatting"
+        "math"
       ]
     },
     {
-      "slug": "isbn-verifier",
-      "uuid": "b902c746-60d1-4645-a5bc-dafadec0ef32",
+      "slug": "palindrome-products",
+      "uuid": "f6799d10-0210-4c73-ac08-d5cac1a00ff3",
       "core": false,
-      "unlocked_by": "bob",
-      "difficulty": 4,
+      "unlocked_by": "space-age",
+      "difficulty": 7,
       "topics": [
+        "algorithms",
         "control_flow_conditionals",
         "control_flow_loops",
-        "pattern_recognition",
-        "regular_expressions"
+        "exception_handling",
+        "integers",
+        "math"
       ]
     },
     {
@@ -527,20 +536,6 @@
         "strings"
       ]
     },
-    {
-      "slug": "word-count",
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-      "core": false,
-      "unlocked_by": "pangram",
-      "difficulty": 1,
-      "topics": [
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-        "lists",
-        "regular_expressions",
-        "strings",
-        "unicode"
-      ]
-    },
     {
       "slug": "acronym",
       "uuid": "440d78d1-9dea-466f-9bd4-935eed067409",
@@ -607,95 +602,6 @@
         "arrays"
       ]
     },
-    {
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-      "uuid": "d003975a-9045-4f03-9ad9-c15db584dc13",
-      "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 5,
-      "topics": [
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-        "integers"
-      ]
-    },
-    {
-      "slug": "perfect-numbers",
-      "uuid": "c6691fd2-e10d-47df-acbf-3adeac5a2f89",
-      "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 3,
-      "topics": [
-        "arrays",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "integers",
-        "math"
-      ]
-    },
-    {
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-      "uuid": "28872cc9-f1ef-487f-9a79-6bf7983148bf",
-      "core": false,
-      "unlocked_by": "space-age",
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-      "topics": [
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "integers",
-        "strings"
-      ]
-    },
-    {
-      "slug": "pythagorean-triplet",
-      "uuid": "394755a3-c743-4b85-b9b8-387907f4e32d",
-      "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 5,
-      "topics": [
-        "algorithms",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "integers",
-        "math"
-      ]
-    },
-    {
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-      "uuid": "7dfa878c-83a6-48ef-9170-b6633d51d601",
-      "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 3,
-      "topics": [
-        "algorithms",
-        "control_flow_loops",
-        "integers",
-        "math"
-      ]
-    },
-    {
-      "slug": "complex-numbers",
-      "uuid": "ea9a9a3e-ae6a-470d-8bb4-2afead507f24",
-      "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 4,
-      "topics": [
-        "math"
-      ]
-    },
-    {
-      "slug": "prime-factors",
-      "uuid": "f43cdddf-eea8-4c4a-8359-c69e20ff9661",
-      "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 4,
-      "topics": [
-        "algorithms",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "integers",
-        "math"
-      ]
-    },
     {
       "slug": "forth",
       "uuid": "e4035939-4375-4720-87ae-e613f925f013",
@@ -784,40 +690,179 @@
         "strings"
       ]
     },
+
     {
-      "slug": "sublist",
-      "uuid": "4be85b5e-6b13-11e7-907b-a6006ad3dba0",
+      "slug": "beer-song",
+      "uuid": "6573f168-d8fc-4ccf-a864-1a61f432fae1",
       "core": false,
-      "unlocked_by": "linked-list",
-      "difficulty": 4,
+      "unlocked_by": "bob",
+      "difficulty": 5,
       "topics": [
-        "arrays",
-        "lists"
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "strings"
       ]
     },
     {
-      "slug": "word-search",
-      "uuid": "0125f5a7-8883-4553-a6c1-45f19544af5e",
+      "slug": "food-chain",
+      "uuid": "62672dc7-e827-4c2e-a282-d6df45b60bbd",
       "core": false,
-      "unlocked_by": "linked-list",
-      "difficulty": 8,
+      "unlocked_by": "bob",
+      "difficulty": 4,
       "topics": [
-        "arrays",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "equality",
-        "optional_values",
-        "parsing",
+        "algorithms",
         "text_formatting"
       ]
     },
     {
-      "slug": "circular-buffer",
-      "uuid": "bf0b1f95-3425-4345-8a12-3a80d49b49c9",
+      "slug": "pig-latin",
+      "uuid": "16e25a38-7ce3-4ccd-b2f0-1550b837fe9b",
       "core": false,
-      "unlocked_by": "linked-list",
-      "difficulty": 8,
-      "topics": [
+      "unlocked_by": "bob",
+      "difficulty": 4,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "games",
+        "regular_expressions",
+        "strings",
+        "transforming"
+      ]
+    },
+    {
+      "slug": "proverb",
+      "uuid": "5626f5b6-207b-458b-92b6-eff2cadb240a",
+      "core": false,
+      "unlocked_by": "bob",
+      "difficulty": 4,
+      "topics": [
+        "arrays",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "optional_values",
+        "strings",
+        "text_formatting"
+      ]
+    },
+    {
+      "slug": "house",
+      "uuid": "a8b7187d-12eb-4efc-b966-87823654ccda",
+      "core": false,
+      "unlocked_by": "bob",
+      "difficulty": 4,
+      "topics": [
+        "arrays",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "recursion",
+        "strings"
+      ]
+    },
+    {
+      "slug": "twelve-days",
+      "uuid": "64de1776-d5c6-43fe-9abf-7e3aa08ae342",
+      "core": false,
+      "unlocked_by": "bob",
+      "difficulty": 4,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "pattern_recognition",
+        "polymorfism",
+        "regular_expressions",
+        "strings"
+      ]
+    },
+    {
+      "slug": "say",
+      "uuid": "12989bb3-c593-4f68-bea4-e2c5b76bc3c0",
+      "core": false,
+      "unlocked_by": "bob",
+      "difficulty": 6,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "exception_handling",
+        "integers",
+        "strings",
+        "text_formatting"
+      ]
+    },
+    {
+      "slug": "isbn-verifier",
+      "uuid": "b902c746-60d1-4645-a5bc-dafadec0ef32",
+      "core": false,
+      "unlocked_by": "bob",
+      "difficulty": 4,
+      "topics": [
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "pattern_recognition",
+        "regular_expressions"
+      ]
+    },
+    {
+      "slug": "diamond",
+      "uuid": "6a1eee0e-f8d4-446d-9c52-f31c3700af1b",
+      "core": false,
+      "unlocked_by": "pascals-triangle",
+      "difficulty": 5,
+      "topics": [
+        "arrays",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "exception_handling",
+        "games",
+        "parsing",
+        "text_formatting"
+      ]
+    },
+    {
+      "slug": "rational-numbers",
+      "uuid": "d8da6cdd-3804-40b0-9821-0dd5765876ff",
+      "core": false,
+      "unlocked_by": "pascals-triangle",
+      "difficulty": 5,
+      "topics": [
+        "algorithms",
+        "floating_point_numbers",
+        "math"
+      ]
+    },
+    {
+      "slug": "sublist",
+      "uuid": "4be85b5e-6b13-11e7-907b-a6006ad3dba0",
+      "core": false,
+      "unlocked_by": "linked-list",
+      "difficulty": 4,
+      "topics": [
+        "arrays",
+        "lists"
+      ]
+    },
+    {
+      "slug": "word-search",
+      "uuid": "0125f5a7-8883-4553-a6c1-45f19544af5e",
+      "core": false,
+      "unlocked_by": "linked-list",
+      "difficulty": 8,
+      "topics": [
+        "arrays",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "equality",
+        "optional_values",
+        "parsing",
+        "text_formatting"
+      ]
+    },
+    {
+      "slug": "circular-buffer",
+      "uuid": "bf0b1f95-3425-4345-8a12-3a80d49b49c9",
+      "core": false,
+      "unlocked_by": "linked-list",
+      "difficulty": 8,
+      "topics": [
         "arrays",
         "control_flow_conditionals",
         "control_flow_loops",
@@ -952,30 +997,71 @@
       ]
     },
     {
-      "slug": "diamond",
-      "uuid": "6a1eee0e-f8d4-446d-9c52-f31c3700af1b",
+      "slug": "strain",
+      "uuid": "8407f9d5-7a7e-40c8-aace-a6a8294ae5e9",
       "core": false,
-      "unlocked_by": "pascals-triangle",
+      "unlocked_by": "list-ops",
+      "difficulty": 4,
+      "topics": [
+        "algorithms",
+        "arrays",
+        "callbacks",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "filtering",
+        "lists"
+      ]
+    },
+    {
+      "slug": "accumulate",
+      "uuid": "6ebe247c-3d11-48b7-8e6f-39f98359d233",
+      "core": false,
+      "unlocked_by": "list-ops",
+      "difficulty": 5,
+      "topics": [
+        "algorithms",
+        "callbacks",
+        "control_flow_loops",
+        "lists"
+      ]
+    },
+    {
+      "slug": "flatten-array",
+      "uuid": "1a6c4a3b-d5db-4a5a-b123-66cf085defe6",
+      "core": false,
+      "unlocked_by": "list-ops",
       "difficulty": 5,
       "topics": [
         "arrays",
+        "recursion"
+      ]
+    },
+    {
+      "slug": "sieve",
+      "uuid": "127287d1-ba44-4400-884a-6fe5f72e210f",
+      "core": false,
+      "unlocked_by": "robot-name",
+      "difficulty": 5,
+      "topics": [
         "control_flow_conditionals",
         "control_flow_loops",
-        "exception_handling",
-        "games",
-        "parsing",
-        "text_formatting"
+        "integers",
+        "math",
+        "recursion"
       ]
     },
     {
-      "slug": "rational-numbers",
-      "uuid": "d8da6cdd-3804-40b0-9821-0dd5765876ff",
+      "slug": "nth-prime",
+      "uuid": "7ce09989-f202-4c3c-8b7e-72cef18808c3",
       "core": false,
-      "unlocked_by": "pascals-triangle",
+      "unlocked_by": "robot-name",
       "difficulty": 5,
       "topics": [
         "algorithms",
-        "floating_point_numbers",
+        "control_flow_conditionals",
+        "control_flow_loops",
+        "exception_handling",
+        "integers",
         "math"
       ]
     },
@@ -1069,43 +1155,29 @@
       ]
     },
     {
-      "slug": "strain",
-      "uuid": "8407f9d5-7a7e-40c8-aace-a6a8294ae5e9",
+      "slug": "sum-of-multiples",
+      "uuid": "f7452f71-795b-40b6-847c-67ef4bb9db45",
       "core": false,
-      "unlocked_by": "list-ops",
-      "difficulty": 4,
+      "unlocked_by": "secret-handshake",
+      "difficulty": 5,
       "topics": [
-        "algorithms",
-        "arrays",
-        "callbacks",
         "control_flow_conditionals",
         "control_flow_loops",
-        "filtering",
-        "lists"
+        "integers",
+        "lists",
+        "math"
       ]
     },
     {
-      "slug": "accumulate",
-      "uuid": "6ebe247c-3d11-48b7-8e6f-39f98359d233",
+      "slug": "change",
+      "uuid": "cfa5741c-9fe9-4cb5-a322-d77ba8145f4b",
       "core": false,
-      "unlocked_by": "list-ops",
-      "difficulty": 5,
+      "unlocked_by": "secret-handshake",
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       "topics": [
         "algorithms",
-        "callbacks",
-        "control_flow_loops",
-        "lists"
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-    {
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-      "uuid": "1a6c4a3b-d5db-4a5a-b123-66cf085defe6",
-      "core": false,
-      "unlocked_by": "list-ops",
-      "difficulty": 5,
-      "topics": [
-        "arrays",
-        "recursion"
+        "performance",
+        "searching"
       ]
     },
     {
@@ -1120,15 +1192,6 @@
         "trees"
       ]
     },
-    {
-      "slug": "point-mutations",
-      "uuid": "6d43709b-3809-4a6a-ab41-2a5ab841b5fb",
-      "core": false,
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-      "difficulty": 0,
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-      "deprecated": true
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     {
       "slug": "darts",
       "uuid": "6c64649b-ea81-4118-9e74-a0a55018ffbc",
@@ -1137,23 +1200,6 @@
       "difficulty": 3,
       "topics": null
     },
-    {
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-      "uuid": "0ba4d3b9-2519-49ac-bd93-f960aca6c11f",
-      "core": false,
-      "unlocked_by": null,
-      "difficulty": 4,
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-        "control_flow_loops",
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-        "integers",
-        "mathematics",
-        "regular_expressions",
-        "strings"
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-    },
     {
       "slug": "run-length-encoding",
       "uuid": "6ac4ad5f-a64a-4646-91c5-169d53f289f9",
@@ -1196,189 +1242,146 @@
       ]
     },
     {
-      "slug": "trinary",
-      "uuid": "1acf1d2d-a25e-4576-94de-0470abc872d9",
+      "slug": "queen-attack",
+      "uuid": "007a4cd4-7324-4512-8905-ead0c78146f7",
       "core": false,
       "unlocked_by": null,
-      "difficulty": 4,
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       "topics": [
         "control_flow_conditionals",
         "control_flow_loops",
-        "integers",
-        "mathematics",
-        "regular_expressions",
-        "strings"
-      ],
-      "deprecated": true
+        "equality",
+        "exception_handling",
+        "optional_values",
+        "parsing",
+        "text_formatting"
+      ]
     },
     {
-      "slug": "sieve",
-      "uuid": "127287d1-ba44-4400-884a-6fe5f72e210f",
+      "slug": "all-your-base",
+      "uuid": "d2d3cd13-b06c-4c24-9964-fb1554f70dd4",
       "core": false,
-      "unlocked_by": "space-age",
+      "unlocked_by": null,
       "difficulty": 5,
       "topics": [
         "control_flow_conditionals",
         "control_flow_loops",
+        "exception_handling",
         "integers",
         "math",
-        "recursion"
+        "parsing"
       ]
     },
     {
-      "slug": "octal",
-      "uuid": "dec66f89-39d0-4857-9679-a035cf4259d7",
+      "slug": "minesweeper",
+      "uuid": "8bafe6c4-9154-4037-9070-7f57f91d495a",
       "core": false,
       "unlocked_by": null,
-      "difficulty": 4,
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-        "control_flow_loops",
-        "integers",
-        "mathematics",
-        "regular_expressions",
-        "strings"
-      ],
-      "deprecated": true
+        "algorithms",
+        "arrays",
+        "games"
+      ]
     },
     {
-      "slug": "hexadecimal",
-      "uuid": "8ed2c9fe-a13f-4313-abf9-125f351c85c9",
+      "slug": "protein-translation",
+      "uuid": "775ae0ec-8db7-4568-a188-963931cf5ee1",
       "core": false,
       "unlocked_by": null,
-      "difficulty": 4,
-      "topics": [
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-        "regular_expressions",
-        "strings"
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-    },
-    {
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-      "uuid": "7ce09989-f202-4c3c-8b7e-72cef18808c3",
-      "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 5,
+      "difficulty": 1,
       "topics": [
         "algorithms",
         "control_flow_conditionals",
         "control_flow_loops",
-        "exception_handling",
-        "integers",
-        "math"
+        "strings"
       ]
     },
     {
-      "slug": "palindrome-products",
-      "uuid": "f6799d10-0210-4c73-ac08-d5cac1a00ff3",
+      "slug": "armstrong-numbers",
+      "uuid": "b28c34f4-f7af-47db-95c6-f920e020bbba",
       "core": false,
-      "unlocked_by": "space-age",
-      "difficulty": 7,
+      "unlocked_by": null,
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         "algorithms",
-        "control_flow_conditionals",
-        "control_flow_loops",
-        "exception_handling",
-        "integers",
         "math"
       ]
     },
+
     {
-      "slug": "sum-of-multiples",
-      "uuid": "f7452f71-795b-40b6-847c-67ef4bb9db45",
+      "slug": "trinary",
+      "uuid": "1acf1d2d-a25e-4576-94de-0470abc872d9",
       "core": false,
-      "unlocked_by": "secret-handshake",
-      "difficulty": 5,
+      "unlocked_by": null,
+      "difficulty": 4,
       "topics": [
         "control_flow_conditionals",
         "control_flow_loops",
         "integers",
-        "lists",
-        "math"
-      ]
+        "mathematics",
+        "regular_expressions",
+        "strings"
+      ],
+      "deprecated": true
     },
     {
-      "slug": "queen-attack",
-      "uuid": "007a4cd4-7324-4512-8905-ead0c78146f7",
+      "slug": "octal",
+      "uuid": "dec66f89-39d0-4857-9679-a035cf4259d7",
       "core": false,
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-      "difficulty": 8,
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         "control_flow_loops",
-        "equality",
-        "exception_handling",
-        "optional_values",
-        "parsing",
-        "text_formatting"
-      ]
+        "integers",
+        "mathematics",
+        "regular_expressions",
+        "strings"
+      ],
+      "deprecated": true
     },
     {
-      "slug": "all-your-base",
-      "uuid": "d2d3cd13-b06c-4c24-9964-fb1554f70dd4",
+      "slug": "hexadecimal",
+      "uuid": "8ed2c9fe-a13f-4313-abf9-125f351c85c9",
       "core": false,
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-      "difficulty": 5,
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         "control_flow_conditionals",
         "control_flow_loops",
-        "exception_handling",
         "integers",
-        "math",
-        "parsing"
-      ]
+        "mathematics",
+        "regular_expressions",
+        "strings"
+      ],
+      "deprecated": true
     },
     {
-      "slug": "minesweeper",
-      "uuid": "8bafe6c4-9154-4037-9070-7f57f91d495a",
+      "slug": "point-mutations",
+      "uuid": "6d43709b-3809-4a6a-ab41-2a5ab841b5fb",
       "core": false,
       "unlocked_by": null,
-      "difficulty": 7,
-      "topics": [
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-      "unlocked_by": "secret-handshake",
-      "difficulty": 8,
-      "topics": [
-        "algorithms",
-        "performance",
-        "searching"
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+      "difficulty": 0,
+      "topics": null,
+      "deprecated": true
     },
     {
-      "slug": "protein-translation",
-      "uuid": "775ae0ec-8db7-4568-a188-963931cf5ee1",
+      "slug": "binary",
+      "uuid": "0ba4d3b9-2519-49ac-bd93-f960aca6c11f",
       "core": false,
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-      "difficulty": 1,
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-        "algorithms",
         "control_flow_conditionals",
         "control_flow_loops",
+        "exception_handling",
+        "integers",
+        "mathematics",
+        "regular_expressions",
         "strings"
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-    },
-    {
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-      "uuid": "b28c34f4-f7af-47db-95c6-f920e020bbba",
-      "core": false,
-      "unlocked_by": null,
-      "difficulty": 2,
-      "topics": [
-        "algorithms",
-        "math"
-      ]
+      ],
+      "deprecated": true
     }
   ]
 }