#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for (int i = 0; i< (n); ++i)
#define repi(i, a, b) for (int i = (a); i < (b); ++i)
#define all(x) (x).begin(), (x).end()
#define fore(i, a) for(auto &i:a)
using ll = long long;

int main() {
	ll h, w, sx, sy, gx, gy;
	cin >> h >> w >> sx >> sy >> gx >> gy;
	sx--;sy--;gx--;gy--;
	vector<vector<ll>> height(h, vector<ll>(w, 0));
	char temp;
	rep(i, h)rep(j, w){
		cin >> temp;
		height[i][j] = temp - '0';
	}
	vector<vector<bool>> is_reachalbe(h, vector<bool>(w, false));
	queue<pair<ll,ll>> q;
	q.push({sx,sy});
	is_reachalbe[sx][sy] = true;
	vector<int> di = {1, 0, -1, 0};
	vector<int> dj = {0, 1, 0, -1};
	auto hantei = [&](ll x, ll y){
		return x >= 0 && x < h && y >= 0 && y < w;
	};
	while(!q.empty()){
		auto[x, y] = q.front();
		q.pop();
		ll nx, ny;
		rep(d, 4){
			nx = x+di[d];ny = y+dj[d];
			if(!hantei(nx,ny) || is_reachalbe[nx][ny]) continue;
			if(abs(height[x][y] - height[nx][ny]) <= 1){
				is_reachalbe[nx][ny] = true;
				q.push({nx,ny});
			}
		}
		ll ax, ay;
		rep(d, 4){
			nx = x+di[d]*2;ny = y+dj[d]*2;
			ax = x+di[d];ay = y+dj[d];
			if(!hantei(nx,ny) || is_reachalbe[nx][ny]) continue;
			if(height[x][y] == height[nx][ny] && height[ax][ay] < height[x][y]){
				is_reachalbe[nx][ny] = true;
				q.push({nx,ny});
			}
		}
	}
	if(is_reachalbe[gx][gy])cout << "YES" << endl;
	else cout << "NO" << endl;






}