The source code for each day can be found in its own folder. When running the excecutable it expects a day argument: -d [day]. It also expects the puzzle input is in a "data.txt" file in the folder of day to be solved. You will have to copy the puzzle inputs into such a file manually. Because everyones input is personalized you will have to get your own input from the AoC website. Lastly blank lines at the end of the file can cause errors, remove them if they cause you trouble.