#include <bits/stdc++.h>
#define rep(i,n) for(int i = 0; i < (n); ++i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
using namespace std;
typedef long long int ll;
typedef pair<int,int> P;
#define yn {puts("YES");}else{puts("NO");}
#define MAX_N 200005

int dx[4] = {-1, 0, 1, 0};
int dy[4] = {0, -1, 0, 1};

int main() {
    int h, w;
    cin >> h >> w;
    int sx, sy, gx, gy;
    cin >> sx >> sy >> gx >> gy;
    sx++; sy++; gx++; gy++;
    string s[h];
    rep(i,h) cin >> s[i];
    int a[h+4][w+4];
    rep(i,h+4){
        rep(j,w+4){
            a[i][j] = 100;
        }
    }
    rep(i,h){
        rep(j,w){
            a[i+2][j+2] = s[i][j] - '0';
        }
    }

    queue<P> que;
    int f[h+4][w+4];
    rep(i,h+4){
        rep(j,w+4){
            f[i][j] = 0;
        }
    }
    que.push(P(sx,sy));

    while(que.size() > 0){
        int x = que.front().first;
        int y = que.front().second;
        que.pop();
        rep(i,4){
            int nx = x + dx[i];
            int ny = y + dy[i];
            if(abs(a[x][y]-a[nx][ny]) <= 1 && f[nx][ny] == 0){
                f[nx][ny] = 1;
                que.push(P(nx,ny));
            }
            nx = x + dx[i]*2;
            ny = y + dy[i]*2;
            if(a[x][y]==a[nx][ny]&&a[(x+nx)/2][(y+ny)/2]<a[x][y]&&f[nx][ny]==0){
                f[nx][ny] = 1;
                que.push(P(nx,ny));
            }
        }
    }

    if(f[gx][gy])yn;
    return 0;
}