Advent of Code 2021 - Solutions My puzzle solutions are targeted for CPython versions 3.9 and up. To execute these solutions, you will need to install the runtime dependencies like so; pip install -r requirements.txt Any of the solutions can be executed as follows: python3 dayXX.py path/to/input.txt or ./dayXX.py path/to/input/txt or cat path/to/input/txt | ./dayXX.py - For more information about the syntax, do: python3 dayXX.py --help