#include <bits/stdc++.h>
using namespace std;
int main()
{
int n, m; cin >> n >> m;
char arr[101][101] = {'x'};
for (int i = 1; i <=100; i++) {
for (int j = 1; j <= 100; j++)arr[i][j] = 'x';
}
for (int i = 1; i <= n; i++)for (int j = 1; j <= m; j++)cin >> arr[i][j];
int x, y;cin >> x >> y;
cout << (arr[x][y - 1] == 'x' && arr[x][y + 1] == 'x' && arr[x - 1][y - 1] == 'x' && arr[x - 1][y + 1] == 'x' && arr[x - 1][y] == 'x' && arr[x + 1][y - 1] == 'x' && arr[x+1][y + 1] == 'x' && arr[x + 1][y]? "yes":"no");
}
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