#include <bits/stdc++.h>
using namespace std;

int h, w, sx, sy, gx, gy;
const int MAX = 55;
int B[MAX][MAX];
int dx[4] = {-1, 1, 0, 0};
int dy[4] = {0, 0, -1, 1};

bool seen[MAX][MAX];

void dfs(int x, int y){
    seen[x][y] = true;
    for(int i = 0; i < 2; i++){
        for(int j = 0; j < 4; j++){
            int nx, ny;
            nx = x + dx[j] * (i + 1);
            ny = y + dy[j] * (i + 1);
            if(nx < 0 or nx >= h or ny < 0 or ny >= w) continue;
            if(seen[nx][ny]) continue;
            if(i == 0){
                if(abs(B[x][y] - B[nx][ny]) > 1) continue;
            }else{
                int bet = B[(x + nx) / 2][(y + ny) / 2];
                if(B[x][y] != B[nx][ny] or B[x][y] < bet) continue;
            }
            dfs(nx, ny);
        }
    }
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

    cin >> h >> w;
    cin >> sx >> sy >> gx >> gy;
    sx--; sy--; gx--; gy--;

    for(int i = 0; i < h; i++){
        string s;
        cin >> s;
        for(int j = 0; j < w; j++){
            B[i][j] = s[j] - '0';
        }
    }

    dfs(sx, sy);

    if(seen[gx][gy]) cout << "YES" << endl;
    else cout << "NO" << endl;



    return 0;
}