#include <bits/stdc++.h>
#include <atcoder/all>
using namespace std;
using namespace atcoder;
// using mint = modint1000000007;
// const int mod = 1000000007;
// using mint = modint998244353;
// const int mod = 998244353;
// const int INF = 1e9;
// const long long LINF = 1e18;
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep2(i, l, r) for (int i = (l); i < (r); ++i)
#define rrep(i, n) for (int i = (n)-1; i >= 0; --i)
#define rrep2(i, l, r) for (int i = (r)-1; i >= (l); --i)
#define all(x) (x).begin(), (x).end()
#define allR(x) (x).rbegin(), (x).rend()
#define P pair<int, int>
template<typename A, typename B> inline bool chmax(A &a, const B &b) { if (a < b) { a = b; return true; } return false; }
template<typename A, typename B> inline bool chmin(A &a, const B &b) { if (a > b) { a = b; return true; } return false; }
const int dx4[4] = { 1, 0, -1, 0 };
const int dy4[4] = { 0, -1, 0, 1 };
int main() {
	std::ios::sync_with_stdio(false);
	std::cin.tie(nullptr);
	int h, w; cin >> h >> w;
	int sx, sy, gx, gy;
	cin >> sx >> sy >> gx >> gy;
	sx--, sy--, gx--, gy--;
	vector<string>s(h);
	rep(i, h)cin >> s[i];
	dsu uf(h * w);
	rep(i, h)rep(j, w) {
		rep(t, 4) {
			int ni = i + dx4[t];
			int nj = j + dy4[t];
			if (ni < 0 || ni >= h)continue;
			if (nj < 0 || nj >= w)continue;
			int n0 = s[i][j] - '0';
			int n1 = s[ni][nj] - '0';
			if (abs(n0 - n1) <= 1) {
				uf.merge(i * w + j, ni*w + nj);
			}
			int ni2 = ni + dx4[t];
			int nj2 = nj + dy4[t];
			if (ni2 < 0 || ni2 >= h)continue;
			if (nj2 < 0 || nj2 >= w)continue;
			int n2 = s[ni2][nj2] - '0';
			if (n0 == n2 && n0 > n1) {
				uf.merge(i * w + j, ni2*w + nj2);
			}
		}
	}
	int x = sx * w + sy;
	int y = gx * w + gy;
	if (uf.same(x, y))cout << "YES" << endl;
	else cout << "NO" << endl;
	return 0;
}