use std::io;
use std::io::BufRead;
use std::collections::HashMap;

#[derive(Clone, PartialEq, Eq, Hash)]
struct Pos { x: usize, y: usize }

#[derive(Clone)]
struct Dir { x: i32, y: i32 }

impl Dir {
    fn rotright(&self) -> Dir {
        Dir { x: -self.y, y: self.x }
    }

    fn rotleft(&self) -> Dir {
        Dir { x: self.y, y: -self.x }
    }
}

enum Choice {
    Left,
    Forward,
    Right,
}

impl Choice {
    fn incr(&mut self) {
        match self {
            Choice::Left => *self = Choice::Forward,
            Choice::Forward => *self = Choice::Right,
            Choice::Right => *self = Choice::Left,
        }
    }

    fn apply(&self, dir: &Dir) -> Dir {
        match self {
            Choice::Left => dir.rotleft(),
            Choice::Forward => dir.clone(),
            Choice::Right => dir.rotright(),
        }
    }
}

struct Cart {
    pos: Pos,
    dir: Dir,
    choice: Choice,
}

impl Cart {
    fn nextpos(&self) -> Pos {
        Pos { x: (self.pos.x as i32 + self.dir.x) as usize,
              y: (self.pos.y as i32 + self.dir.y) as usize }
    }
}

fn newdir(dir: &Dir, c: u8) -> Dir {
    // println!(" newdir {},{} {}", dir.x, dir.y, std::char::from_u32(c as u32).unwrap());
    if c == '|' as u8 || c == '-' as u8 {
        Dir { x: dir.x, y: dir.y }
    } else if c == '/' as u8 {
        if dir.y == 0 {
            dir.rotleft()
        } else {
            dir.rotright()
        }
    } else if c == '\\' as u8 {
        if dir.y == 0 {
            dir.rotright()
        } else {
            dir.rotleft()
        }
    } else {
        println!("<{}>", c);
        unreachable!();
    }
}

fn print_dir(dir: &Dir) -> char {
    match dir {
        Dir{x:1,y:0} => '>',
        Dir{x:-1,y:0} => '<',
        Dir{x:0,y:1} => 'v',
        Dir{x:0,y:-1} => '^',
        Dir{..} => '?',
    }
}

fn print_grid(grid: &Vec<Vec<u8>>, carts: &Vec<Cart>) {
    let mut hascart: HashMap<Pos, usize> = HashMap::new();
    for (i, cart) in carts.iter().enumerate() {
        hascart.insert(cart.pos.clone(), i);
    }

    for y in 0..grid.len() {
        for x in 0..grid[y].len() {
            match hascart.get(&Pos { x, y }) {
                Some(&idx) => {
                    print!("{}", print_dir(&carts[idx].dir));
                }
                None => {
                    print!("{}", std::char::from_u32(grid[y][x] as u32).unwrap());
                }
            }
        }

        println!("");
    }
}

pub fn main<T: BufRead>(reader: T) -> io::Result<(String, String)> {
    let mut grid: Vec<Vec<u8>> = reader.lines().map(|l| l.unwrap().as_bytes().to_vec()).collect();
    let h = grid.len();
    let w = grid[0].len();

    let mut hascart = Vec::new();
    for _ in 0..h {
        hascart.push(vec![false; w]);
    }

    let mut carts: Vec<Cart> = Vec::new();
    for y in 0..h {
        for x in 0..w {
            macro_rules! grid_process {
                ( $c1:expr, $c2:expr, $dx:expr, $dy:expr ) => {
                    if grid[y][x] == $c1 as u8 {
                        grid[y][x] = $c2 as u8;
                        carts.push(Cart { pos: Pos { x, y }, dir: Dir { x: $dx, y: $dy }, choice: Choice::Left });
                        hascart[y][x] = true;
                    }
                }
            }

            grid_process!('>', '-', 1, 0);
            grid_process!('<', '-', -1, 0);
            grid_process!('^', '|', 0, -1);
            grid_process!('v', '|', 0, 1);
        }
    }

    let mut first_crash = None;
    let part2;

    loop {
        let mut to_remove = Vec::new();

        for (i, mut cart) in carts.iter_mut().enumerate() {
            if !hascart[cart.pos.y][cart.pos.x] {
                to_remove.push(i);
                continue;
            }

            let pos2 = cart.nextpos();
            let c = grid[pos2.y][pos2.x];

            // println!("cart at {},{} {},{}", cart.pos.x, cart.pos.y, cart.dir.x, cart.dir.y);

            let dir2;
            if c == '+' as u8 {
                dir2 = cart.choice.apply(&cart.dir);
                cart.choice.incr();
            } else {
                dir2 = newdir(&cart.dir, c);
            }

            hascart[cart.pos.y][cart.pos.x] = false;

            if hascart[pos2.y][pos2.x] {
                if first_crash.is_none() {
                    first_crash = Some(pos2.clone());
                }

                to_remove.push(i);
                hascart[pos2.y][pos2.x] = false;
            } else {
                hascart[pos2.y][pos2.x] = true;
                cart.pos = pos2;
                cart.dir = dir2;
            }
        }

        for idx in to_remove {
            carts.swap_remove(idx);
        }

        if carts.len() == 1 {
            part2 = format!("{},{}", carts[0].pos.x, carts[0].pos.y);
            break;
        }

        carts.sort_by_key(|cart| (cart.pos.y, cart.pos.x));

        // print_grid(&grid, &carts);
    }

    let part1 = match first_crash {
        Some(pos) => format!("{},{}", pos.x, pos.y),
        None => unreachable!()
    };

    Ok((part1, part2))
}