#include <algorithm>
#include <cstdio>
#include <cstdlib>
#include <cctype>
#include <cmath>
#include <iostream>
#include <queue>
#include <list>
#include <stack>
#include <map>
#include <numeric>
#include <set>
#include <sstream>
#include <string>
#include <vector>
using namespace std;
#define REP(i,a,n) for(int i=(a); i<(int)(n); i++)
#define rep(i,n) REP(i,0,n)
#define FOR(it,c) for(__typeof((c).begin()) it=(c).begin(); it!=(c).end(); ++it)
#define ALLOF(c) (c).begin(), (c).end()
typedef long long ll;

string field[55];
int visited[55][55];

int vx[4] = {0,0,1,-1};
int vy[4] = {1,-1,0,0};

int main(){
  ios::sync_with_stdio(false);
  int H, W;
  cin >> H >> W;
  int sx, sy, gx, gy;
  cin >> sx >> sy >> gx >> gy;
  rep(i,H){
    cin >> field[i];
  }

  sx--;
  sy--;
  gx--;
  gy--;
  pair<int,int> p(sx, sy);
  queue< pair<int,int> > que;
  que.push(p);

  while(!que.empty()){
    p = que.front(); que.pop();
    if(visited[p.first][p.second] == 1) continue;
    visited[p.first][p.second] = 1;
    
    if(p.first == gx && p.second == gy){
      cout << "YES" << endl;
      return 0;
    }

    rep(k,8){
      int nx = p.first + vx[k];
      int ny = p.second + vy[k];

      if(0<=nx && nx<H && 0<=ny && ny<W &&
         abs((field[p.first][p.second]-'0') - (field[nx][ny]-'0')) <= 1){
        que.push( make_pair(nx, ny) );
      }

      int n2x = p.first + 2*vx[k];
      int n2y = p.second + 2*vy[k];
      if(0<=n2x && n2x<H && 0<=n2y && n2y<W &&
         (field[p.first][p.second] == field[n2x][n2y])){
        que.push( make_pair(n2x, n2y) );
      }
      
    }
  }
  
  cout << "NO" << endl;
  return 0;
}