#include <bits/stdc++.h>
using namespace std;
#define all(c) (c).begin(),(c).end()
#define rrep(i,n) for(int i=(int)(n)-1;i>=0;i--)
#define REP(i,m,n) for(int i=(int)(m);i<(int)(n);i++)
#define rep(i,n) REP(i,0,n)
#define iter(c) __typeof((c).begin())
#define tr(it,c) for(iter(c) it=(c).begin();it!=(c).end();it++)
#define mem(a) memset(a,0,sizeof(a))
#define pd(a) printf("%.10f\n",a)
#define pb(a) push_back(a)
#define in(a) insert(a)
#define pi M_PI
#define R cin>>
#define F first
#define S second
#define C class
#define ll long long
#define ln cout<<'\n'
template<C T>void pr(T a){cout<<a;ln;}
template<C T,C T2>void pr(T a,T2 b){cout<<a<<' '<<b;ln;}
template<C T,C T2,C T3>void pr(T a,T2 b,T3 c){cout<<a<<' '<<b<<' '<<c;ln;}
template<C T>void PR(T a,int n){rep(i,n){if(i)cout<<' ';cout<<a[i];}ln;}
bool check(int n,int m,int x,int y){return x>=0&&x<n&&y>=0&&y<m;}
const ll MAX=1000000007,MAXL=1LL<<60,dx[4]={-1,0,1,0},dy[4]={0,1,0,-1};
typedef pair<int,int> P;

void Main() {
  int n,m;
  cin >> n >> m;
  int sx,sy,tx,ty;
  cin >> sx >> sy >> tx >> ty;
  sx--,sy--,tx--,ty--;
  string s[n];
  rep(i,n) cin >> s[i];
  int d[n][m];
  mem(d);
  d[sx][sy]=1;
  queue<P> que;
  que.push(P(sx,sy));
  while(!que.empty()) {
    P p=que.front();que.pop();
    rep(i,4) {
      int x=p.F+dx[i],y=p.S+dy[i];
      if(!check(n,m,x,y)) continue;
      int xx=s[p.F][p.S]-'0',yy=s[x][y]-'0';
      if(abs(xx-yy)<=1&&!d[x][y]) {
        d[x][y]=1;
        que.push(P(x,y));
      }
      if(xx<=yy) continue;
      x+=dx[i],y+=dy[i];
      if(!check(n,m,x,y)) continue;
      yy=s[x][y]-'0';
      if(abs(xx-yy)==0&&!d[x][y]) {
        d[x][y]=1;
        que.push(P(x,y));
      }
    }
  }
  if(d[tx][ty]) pr("YES");
  else pr("NO");
}

int main() {
  ios::sync_with_stdio(0);cin.tie(0);
  Main();return 0;
}