#include <stdio.h>

char buf[50][100];
char visit[50][100];

int solve(int x, int y, int gx, int gy)
{
	int dx, dy;

	if (visit[y][x]) {
		return 0;
	}
	visit[y][x] = 1;

	fprintf(stderr, "in %d %d %d %d\n", x, y, gx, gy);
	if (x == gx && y == gy) {
		fprintf(stderr, "OK\n");
		return 1;
	}
	int base = buf[y][x];
	fprintf(stderr, "baseptr=%s\n", buf[y]);
	fprintf(stderr, "base = %c\n", base);

	if (base == 0) {
		fprintf(stderr, "fail\n");
		return 0;
	}
	int dxdy[4][2] = {
		{ -1, 0 },
		{ 1, 0 },
		{ 0, -1 },
		{ 0, 1 },
	};
	for (int i = 0; i < 4; i++) {
		dx = dxdy[i][0];
		dy = dxdy[i][1];

		int xx = x + dx;
		int yy = y + dy;
		if (xx < 0 || yy < 0 || xx >= 50 || yy >= 50) {
			continue;
		}
		int c = buf[yy][xx];
		if (c == base - 1 || c == base + 1 || c == base) {
			if (solve(xx, yy, gx, gy)) {
				fprintf(stderr, "solved\n");
				return 1;
			}
		}

		xx = x + dx * 2;
		yy = y + dy * 2;
		if (xx < 0 || yy < 0 || xx >= 50 || yy >= 50) {
			continue;
		}
		int xx2 = x + dx;
		int yy2 = y + dy;

		c = buf[yy2][xx2];
		if (c >= base) {
			continue;
		}
		c = buf[yy][xx];
		if (c == base) {
			if (solve(xx, yy, gx, gy)) {
				fprintf(stderr, "solved\n");
				return 1;
			}
		}
	}
	return 0;
}

main()
{
	int w, h, sx, sy, gx, gy;

	scanf("%d %d\n", &h, &w);
	scanf("%d %d %d %d\n", &sx, &sy, &gx, &gy);
	int n = 0;
	while (gets(buf[n]) != NULL) {
		n++;
	}

	sx--;
	sy--;
	gx--;
	gy--;
	if (solve(sy, sx, gy, gx)) {
		puts("YES");
	} else {
		puts("NO");
	}
}