package no424;

import java.util.ArrayDeque;
import java.util.Queue;
import java.util.Scanner;

public class Main {
	static int[] D = {1,0,-1,0};
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		int h = sc.nextInt();
		int w = sc.nextInt();
		int[][] m = new int[h][w];
		int si = sc.nextInt() - 1;
		int sj = sc.nextInt() - 1;
		int gi = sc.nextInt() - 1;
		int gj = sc.nextInt() - 1;
		for(int i=0;i<h;i++) {
			String s = sc.next();
			for(int j=0;j<w;j++) {
				m[i][j] = s.charAt(j) - '0';
			}
		}
		boolean[][] used = new boolean[h][w];
		Queue<Integer> q = new ArrayDeque<>();
		q.offer(si * 100 + sj);
		used[si][sj] = true;
		while(!q.isEmpty()) {
			int c = q.poll();
			int ci = c / 100;
			int cj = c % 100;
			for(int k=0;k<4;k++) {
				int ni = ci + D[k];
				int nj = cj + D[k^1];
				if (ni < 0 || ni >= h || nj < 0 || nj >= w) {
					continue;
				}
				if (Math.abs(m[ci][cj] - m[ni][nj]) <= 1 && !used[ni][nj]) {
					used[ni][nj] = true;
					q.offer(ni * 100 + nj);
				}
				int ii = ni;
				int jj = nj;
				ni += D[k];
				nj += D[k^1];
				if (ni < 0 || ni >= h || nj < 0 || nj >= w) {
					continue;
				}
				if (m[ci][cj] == m[ni][nj]  && m[ci][cj] > m[ii][jj] && !used[ni][nj]) {
					used[ni][nj] = true;
					q.offer(ni * 100 + nj);
				}
			}
		}
		System.out.println(used[gi][gj] ? "YES" : "NO");
	}

}