#include <cstdio>
#include <cstring>
#include <string>
#include <cmath>
#include <cassert>
#include <iostream>
#include <algorithm>
#include <stack>
#include <queue>
#include <vector>
#include <set>
#include <map>
#include <bitset>
using namespace std;

#define repl(i,a,b) for(int i=(int)(a);i<(int)(b);i++)
#define rep(i,n) repl(i,0,n)
#define mp(a,b) make_pair(a,b)
#define pb(a) push_back(a)
#define all(x) (x).begin(),(x).end()
#define dbg(x) cout<<#x"="<<x<<endl
#define fi first
#define se second

#define INF 2147483600
typedef pair<int, int> P;

int main(){
  int h,w,sx,sy,gx,gy;
  cin>>h>>w>>sx>>sy>>gx>>gy;

  vector<vector<int> > f(h, vector<int>(w));
  vector<vector<bool> > visited(h, vector<bool>(w,false));

  rep(i,h){
    string s;
    cin>>s;
    rep(j,w){
      f[i][j] = s[j]-'0';
    }
  }

  const int dx[] = {0,0,-1,1}, dy[] = {1,-1,0,0};
  queue<P> q;
  q.push(mp(sx-1,sy-1));
  visited[sx-1][sy-1]=true;
  gx--;gy--;

  while(!q.empty()){
    P p=q.front(); q.pop();
    int x=p.fi, y=p.se;

    if(x==gx && y==gy){
      cout<<"YES"<<endl;
      return 0;
    }

    rep(i,4){
      int nx=x+dx[i],ny=y+dy[i];
      if(nx>=0 && nx<h && ny>=0 && ny<w && visited[nx][ny]==false && abs(f[x][y]-f[nx][ny])<=1){
        visited[nx][ny]=true;
        q.push(mp(nx,ny));
      }
    }

    rep(i,4){
      int nx=x+2*dx[i],ny=y+2*dy[i];
      if(nx>=0 && nx<h && ny>=0 && ny<w && visited[nx][ny]==false && f[x][y]==f[nx][ny] && f[x+dx[i]][y+dy[i]]<f[x][y]){
        visited[nx][ny]=true;
        q.push(mp(nx,ny));
      }
    }
  }

  cout<<"NO"<<endl;

  return 0;
}