pub fn solve(input: &str) {
    let grid = input.lines().map(|str| str.as_bytes()).collect::<Vec<_>>();
    let width = grid[0].len() as i32;
    let height = grid.len() as i32;
    let words = ((b'M', b'A', b'S'), (b'S', b'A', b'M'));

    let mut matches = 0;

    for xpos in 1..(width - 1) {
        for ypos in 1..(height - 1) {
            if grid[xpos as usize][ypos as usize] == b'A' {
                let left = (grid[(xpos - 1) as usize][(ypos - 1) as usize],
                            grid[(xpos) as usize][(ypos) as usize],
                            grid[(xpos + 1) as usize][(ypos + 1) as usize]);
                let right = (grid[(xpos + 1) as usize][(ypos - 1) as usize],
                             grid[(xpos) as usize][(ypos) as usize],
                             grid[(xpos - 1) as usize][(ypos + 1) as usize]);
                
                if (left == words.0 || left == words.1) && (right == words.0 || right == words.1) {
                    matches += 1;
                }
            }
        }
    }

    println!("matches: {}", matches);
}