pub trait Day: std::fmt::Debug {
    fn part1(&mut self) -> String;
    fn part2(&mut self) -> String;
    fn parse(&mut self) {}
    fn solve(&mut self, part: u8) -> String {
        self.parse();
        match part {
            1 => self.part1(),
            2 => self.part2(),
            _ => panic!("Invalid part #"),
        }
    }
}