# -*- coding: utf-8 -*-
"""
No.424 立体迷路
https://yukicoder.me/problems/no/424

"""
import sys
from sys import stdin
from collections import deque
input = stdin.readline


def bfs(maze, sx, sy, gx, gy, h, w):
    explored = [[False] * w for _ in range(h)] #  各マスが探索済かどうかのフラグ
    Q = deque()
    Q.append((sx, sy))
    while Q:
        cx, cy = Q.popleft()    #  現在地の座標
        ch = maze[cy][cx]       #  現在のマスの高さ

        # 隣りの同じ高さのブロックに歩いて移動 または 隣りの±1の高さのブロックにはしごをかけて移動
        dx = [0, 0, -1, 1]
        dy = [-1, 1, 0, 0]
        for i in range(len(dx)):
            nx = cx + dx[i]
            ny = cy + dy[i]
            if (0 <= nx < w) and (0 <= ny < h) and explored[ny][nx] is False:
                nh = maze[ny][nx] #  移動先のマスの高さ
                if ch-1 <= nh <= ch+1:
                    if nx == gx and ny == gy:
                        return 'YES'
                    Q.append((nx, ny))
                    explored[ny][nx] = True

        # 2ブロック先の同じ高さのマスにはしごを渡して移動
        dx = [0, 0, -2, 2]
        dy = [-2, 2, 0, 0]
        for i in range(len(dx)):
            nx = cx + dx[i]
            ny = cy + dy[i]
            if (0 <= nx < w) and (0 <= ny < h) and explored[ny][nx] is False:
                nh = maze[ny][nx] #  移動先のマスの高さ
                mh = maze[(ny+cy)//2][(nx+cx)//2] # 間にあるマスの高さ
                if nh == ch and mh <= ch:
                    if nx == gx and ny == gy:
                        return 'YES'
                    Q.append((nx, ny))
                    explored[ny][nx] = True
    return 'NO'


def main(args):
    h, w = map(int, input().split())
    sy, sx, gy, gx = map(int, input().split()) #  h方向がx、w方向がyなので注意
    maze = []
    for _ in range(h):
        maze.append([int(x) for x in list(input().strip())])
    ans = bfs(maze, sx-1, sy-1, gx-1, gy-1, h, w) #  入力は1起算なので-1する
    print(ans)


if __name__ == '__main__':
    main(sys.argv[1:])