struct Ant {
    x: usize,
    y: usize,
    dir: Direction
}

#[derive(Clone,Copy)]
enum Direction {
    North,
    East,
    South,
    West
}

use Direction::*;

impl Ant {
    fn mv(&mut self, vec: &mut Vec<Vec<u8>>) {
        let pointer = &mut vec[self.y][self.x];