#include <bits/stdc++.h>
#include <iostream>
using namespace std;
int main ()
{
    int n,m;
    cin  >> n >> m;
    char grid [n+2][m+2];
    for (int i=0;i<n+2; i++){
        for (int j=0;j<m+2 ;j++){
            grid[i][j]= 'x';
        }
    }
    for (int i=1 ;i<=n ;i++){
        for (int j =1 ;j<=m ;j++){
            cin >> grid[i][j];
        }
    }
    int i,j;
    cin>>i>>j;
    if (grid[i-1][j-1]=='x' and grid [i-1][j] =='x' and grid [i-1][j+1]=='x' and
        grid[i][j-1]=='x' and grid [i][j+1] =='x' and grid [i+1][j-1]=='x' and
        grid[i+1][j]=='x' and grid [i+1][j+1] =='x' )
        {
            cout << "yes\n";
        }
        else
        {
            cout <<"no\n";

        }
        return 0;
}