Here's some info on Advent of Code 2018. It's basically a series of coding puzzles. This year I'm doing them in C# in an effort to learn that language a little better. I'm pretty comfortable with it but this is good practice. There's a few spots where I got stuck on syntax or confused by the... "verbose"... narrative, and had to use other posted solutions as a reference. I've tried to point those spots out in the code or commit messages, but I'm not perfect, and it's all for fun anyway.
Speaking of fun, this challenge is a blast, and it's all put together by volunteers. It's been a nice way to challenge yourself in December.