#include <bits/stdc++.h>
#define rep(x, to) for (int x = 0; x < (to); x++)
#define REP(x, a, to) for (int x = (a); x < (to); x++)
#define EPS (1e-14)
#define _PA(x,N) rep(i,N){cout<<x[i]<<" ";}cout<<endl;
#define _PA2(x,H,W) rep(i,(H)){rep(j,(W)){cout<<x[i][j]<<" ";}cout<<endl;}


using namespace std;

typedef long long ll;
typedef pair<int, int> PII;
typedef pair<ll, ll> PLL;
typedef complex<double> Complex;
typedef vector< vector<int> > Mat;

int dx[] = {1, 0, -1, 0};
int dy[] = {0, 1, 0, -1};

int h, w;
int sx, sy, gx, gy;
string b[55];
int f[55][55];

char visit[55][55];

void dfs(int y, int x) {
	if (visit[y][x]) return;
	visit[y][x] = 1;
	for (int i = 0; i < 4; i++) {
		int ny = y + dy[i];
		int nx = x + dx[i];
		if (ny < 0 || ny >= h) continue;
		if (nx < 0 || nx >= w) continue;
		if (f[ny][nx] - 1 <= f[y][x] && f[y][x] <= f[ny][nx] + 1) {
			dfs(ny, nx);
		} else if (f[y][x] - f[ny][nx] >= 2) {
			ny += dy[i];
			nx += dx[i];
			if (ny < 0 || ny >= h) continue;
			if (nx < 0 || nx >= w) continue;
			if (f[ny][nx] != f[y][x]) continue;
			dfs(ny, nx);
		}
	}
}

void solve() {
	dfs(sy, sx);
	if (visit[gy][gx]) {
		cout << "YES" << endl;
	} else {
		cout << "NO" << endl;
	}
}

int main() {
	cin >> h >> w;
	cin >> sx >> sy >> gx >> gy;
	sx--, sy--, gx--, gy--;
	swap(sy, sx);
	swap(gy ,gx);
	for (int i = 0; i < h; i++) {
		cin >> b[i];
	}
	for (int i = 0; i < h; i++) {
		for (int j = 0; j < w; j++) {
			f[i][j] = b[i][j] - '0';
		}
	}

	solve();
	return 0;
}