use std::collections::VecDeque;

const DX: [isize; 8] = [-1, 1, 0, 0, -2, 2, 0, 0];
const DY: [isize; 8] = [0, 0, -1, 1, 0, 0, -2, 2];

fn main() {
    let mut hw = String::new();
    std::io::stdin().read_line(&mut hw).ok();
    let hw: Vec<usize> = hw.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let h = hw[0];
    let w = hw[1];
    let mut temp = String::new();
    std::io::stdin().read_line(&mut temp).ok();
    let temp: Vec<usize> = temp.trim().split_whitespace().map(|s| s.parse().unwrap()).collect();
    let sx = temp[0]-1;
    let sy = temp[1]-1;
    let gx = temp[2]-1;
    let gy = temp[3]-1;
    let grid = (0..h).map(|_| {
            let mut temp = String::new();
            std::io::stdin().read_line(&mut temp).ok();
            temp.trim().chars().map(|c| c as isize - '0' as isize).collect::<Vec<_>>()
        })
        .collect::<Vec<_>>();

    let mut deque = VecDeque::new();
    deque.push_back((sx, sy));
    let mut checked = vec![vec![false; w]; h];
    checked[sx][sy] = true;
    while let Some((x, y)) = deque.pop_front() {
        for dir in 0..8 {
            let nx = x as isize + DX[dir];
            let ny = y as isize + DY[dir];
            if nx >= 0 && ny >= 0 && nx < h as isize && ny < w as isize {
                let nx = nx as usize;
                let ny = ny as usize;
                if checked[nx][ny] { continue; }
                if dir < 4 && (grid[x][y] - grid[nx][ny]).abs() > 1 { continue; }
                if dir >= 4 && grid[x][y] != grid[nx][ny] { continue; }
                checked[nx][ny] = true;
                deque.push_back((nx, ny));
            }
        }
    }
    if checked[gx][gy] {
        println!("YES");
    } else {
        println!("NO");
    }
}