' . ' 才是空地

#include <iostream>
using namespace std;
int dx[] = {0, 1, 0, -1}, dy[] = {1, 0, -1, 0};
int n, m, fx, fy, sx, sy;
const int N = 10;
char a[N][N];
bool st[N][N];
int cnt = 0;
bool flag;
void dfs(int x, int y)
{
    if (x == fx && y == fy){
        flag = true;
        return ;
    }
    st[x][y] = true;
    for (int i = 0; i < 4; i ++){
        int nx = x + dx[i];
        int ny = y + dy[i];
        if (nx <= 0 || ny <= 0 || nx > n || ny > m)continue;
        if (!st[nx][ny] && a[nx][ny] == '.'){
//            st[nx][ny] = true;
            dfs(nx, ny);
//            st[nx][ny] = false;
        }

    }
}
int main()
{
    cin >> n >> m ;
    cin >> sx >> sy >> fx >> fy;
    for (int i = 1; i <= n; i ++){
        for (int j = 1; j <= m; j ++){
            cin >> a[i][j];
        }
    }
    st[sx][sy] = true;
    dfs(sx, sy);
    if (flag)cout << "YES";
    else cout << "NO";
    return 0;
}