Advent of Code is a yearly Challenge hosted yearly by Eric Wastl over the first 25 days of December. You can read more about it here: About Advent of Code
Since the author has explicitly stated that they'd rather participants not copy things from the website, none of the input or example files will be found for this Challenge.
You can, however, visit the website--it's completely free to do so! Just be aware that you'd need to be logged in to be able to obtain full input files.