2 https://www.youtube.com/watch?v=gibVyxpi-qA
5 https://gist.github.com/mcpower/87427528b9ba5cac6f0c679370789661
8 https://github.com/epsalon/advent_of_code
11 https://blog.vero.site/post/advent-leaderboard
12 https://www.youtube.com/watch?v=jls4zhEhlog
15 increment a visual block
16 visual-block <number> g Ctrl-A (or Ctrl-X decrements)