#include <iostream>
#include <string>
using namespace std;

int H, W;
int sx,sy,gx,gy;
string field[150];
int check[150][150];

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

void dfs(int sy, int sx){
    if(sx==gx-1&&sy==gy-1)return;
    for(int i=0;i<4;i++){
        if (!check[sy+dy[i]][sx+dx[i]] && sx+dx[i] >= 0 && sx+dx[i] <= W && sy+dy[i] >= 0 && sy+dy[i] <= H){
            if(field[sy][sx] - '0' == field[sy+dy[i]][sx+dx[i]] - '0'){
                check[sy + dy[i]][sx + dx[i]] = check[sy][sx] + 1;
                dfs(sy + dy[i], sx + dx[i]);
            }else if (field[sy + dy[i]][sx + dx[i]] - '0' - 1 == field[sy][sx] - '0'){
                check[sy + dy[i]][sx + dx[i]] = check[sy][sx] + 1;
                dfs(sy + dy[i], sx + dx[i]);
            }else if (field[sy + dy[i]][sx + dx[i]] - '0' < field[sy][sx] - '0'){
                if (field[sy + dy[i]][sx + dx[i]] - '0' == field[sy][sx] - '0' - 1){
                    check[sy + dy[i]][sx + dx[i]] = check[sy][sx] + 1;
                    dfs(sy + dy[i], sx + dx[i]);
                }else if (sx + dx[i] + dx[i] >= 0 && sx + dx[i] + dx[i] <= W && sy + dy[i] + dy[i] >= 0 && sy + dy[i] + dy[i] <= H && !check[sy + dy[i] + dy[i]][sx + dx[i] + dx[i]] && field[sy][sx] - '0' == field[sy + dy[i] + dy[i]][sx + dx[i] + dx[i]] - '0'){
                    check[sy + dy[i] + dy[i]][sx + dx[i] + dx[i]] = check[sy][sx] +1;
                    dfs(sy + dy[i] + dy[i], sx + dx[i] + dx[i]);
                }
            }

        }
    }
    return;
}

int main(){
    cin >> H >> W;
    cin>>sx>>sy>>gx>>gy;

    for(int i=0;i<H;i++){
        cin>>field[i];
    }
    check[sx-1][sy-1] = 1;
    dfs(sx-1,sy-1);

    if(check[gx-1][gy-1]){
        cout<<"YES"<<endl;
    }else{
        cout<<"NO"<<endl;
    }
}