#pragma GCC optimize ("O3")
#pragma GCC target ("avx")
#pragma GCC optimize ("Ofast")
#include <cstdio>
#include <cctype>
using namespace std;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define FOR(i, m, n) for (int i = (m); i < (n); ++i)

inline int gc()noexcept { return getchar_unlocked(); }
inline int in()noexcept {
	int v = 0; char c = gc();
	for (; isdigit(c); c = gc()) {
		v *= 10;
		v += c - '0';
	}
	return v;
}

int par[2509];
inline int root(int x)noexcept {
	if (par[x] == x)return x;
	else return par[x] = root(par[x]);
}
inline void unite(int x, int y)noexcept {
	x = root(x); y = root(y);
	if (x == y)return;
	par[y] = x;
}

int s[51][51];

inline bool check(int x, int y)noexcept {
	return x >= y ? x <= y + 1 : y == x + 1;
}

int main() {
	int h = in(), w = in();
	int sx = in() - 1, sy = in() - 1;
	int gx = in() - 1, gy = in() - 1;
	rep(i, h) {
		rep(j, w)s[i][j] = gc() - '0';
		gc();
	}

	int n = h * w;
	rep(i, n)par[i] = i;

	int ind = 0;
	rep(i, h) {
		rep(j, w - 1) {
			if (check(s[i][j], s[i][j + 1])) {
				unite(ind, ind + 1);
			}
			++ind;
		}
		++ind;
	}
	ind = 0;
	rep(i, h - 1) {
		rep(j, w) {
			if (check(s[i][j], s[i + 1][j])) {
				unite(ind, ind + w);
			}
			++ind;
		}
	}
	ind = 0;
	rep(i, h) {
		rep(j, w - 2) {
			if (s[i][j] == s[i][j + 2] && s[i][j] > s[i][j + 1]) {
				unite(ind, ind + 2);
			}
			++ind;
		}
		ind += 2;
	}
	ind = 0;
	rep(i, h - 2) {
		rep(j, w) {
			if (s[i][j] == s[i + 2][j] && s[i][j] > s[i + 1][j]) {
				unite(ind, ind + w + w);
			}
			++ind;
		}
	}

	if (root(sx * w + sy) == root(gx * w + gy)) {
		puts("YES");
	} else {
		puts("NO");
	}
}