Day 1: Gives wrong answer
Day 2: Complete, requires some changes to go from part 1 to part 2
Day 3: Part 1 complete, part 2 not started
Day 4: Complete
Day 5: Complete
Day 6: Complete
Day 7: Complete
Day 8: Started... looks hard
Day 9: Started
...
Day 16: Complete, part 2 takes a long time to run
...
Day 24: I'll get back to this later