#define _CRT_SECURE_NO_WARNINGS // #pragma warning(disable:4996)
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <vector>
#include <string>
#include <queue>
#include <functional>
#include <sstream>
#include <cmath>
#include <set>
#include <map>
#include <stack>
using namespace std; 

#define rep(i,a,b) for(int i=(a);i<(b);i++)
#define rrep(i,a,b) for(int i=(a);i>=(b);i--)
#define pb push_back
#define mp(a,b) make_pair(a,b)
#define all(a) a.begin(),a.end()
#define len(x) ((int)(x).size())
#define tmax(a,b,c) max((a),max((b),(c)))
#define tmin(a,b,c) min((a),min((b),(c)))
#define debug(x) cerr << #x << " is " << x << endl;
#define debug2(x,y) cerr << #x << " is " << x << " " << #y << " is " << y << endl;
#define debuga(g,h,w) rep(i,0,h) { rep(j,0,w) cout << g[i][j] << " "; cout << endl;}
#define debugv(v) for(auto&& x : v){cout << x << " ";} cout << endl;

typedef pair<int, int> Pii;
typedef map<int, int> Mii;
typedef vector<int> Vi;
typedef vector<vector<int> > VVi;
typedef long long ll;
const int inf = 2e9;
const ll ll_inf = 1e17;
const int mod = 1e9 + 7;
const long double eps = 1e-10;
typedef pair<ll, ll> Pll; 

int h, w;
int sx, sy, gx, gy;
int g[51][51];
int dx[4] = {0,1,0,-1}; // nesw
int dy[4] = {1,0,-1,0};
int used[51][51];

int main()
{
	cin >> h >> w;
	cin >> sy >> sx >> gy >> gx;
	sx--; sy--; gx--; gy--;
	rep(i,0,h) rep(j,0,w) {
		char c; cin >> c;
		g[i][j] = (int)(c - '0');
	}
	//debuga(g,h,w);

	queue<Pii> que;
	que.push(mp(sy,sx));
	used[sy][sx] = true;
	while (!que.empty()) {
		Pii p = que.front(); que.pop();
		int by = p.first, bx = p.second;
		if (bx == gx && by == gy) {
			cout << "YES" << endl;
			return 0;
		}

		int height = g[by][bx];
		//printf("height=%d by=%d bx=%d\n",height,by,bx);
		rep(i,0,4) {
			int nx = bx + dx[i];
			int ny = by + dy[i];
			if (nx < 0 || ny < 0 || nx >= w || ny >= h) continue;
			if (used[ny][nx]) continue;
			int t = g[ny][nx];
			if (height-1 <= t && t <= height+1) {
				que.push(mp(ny,nx));
				used[ny][nx] = true;
			}
		}
		rep(i,0,4) {
			int nx = bx + dx[i] + dx[i];
			int ny = by + dy[i] + dy[i];
			if (nx < 0 || ny < 0 || nx >= w || ny >= h) continue;
			if (used[ny][nx]) continue;
			int t = g[ny][nx];
			if (t == height && g[by+dy[i]][bx+dx[i]] < t) {
				que.push(mp(ny,nx));
				used[ny][nx] = true;
			}
		}
	}
	cout << "NO" << endl;
	return 0;
}