#include <bits/stdc++.h>
using namespace std;
#define REP(i,a) for(int i = 0; i < (a); i++)
#define ALL(a) (a).begin(),(a).end()
typedef long long ll;
typedef pair<int, int> P;
const int INF = 1e9;
const int MOD = 1e9 + 7;

struct UnionFind{
    vector<int> par;
    vector<int> siz;

    UnionFind(int n){
        init(n);
    }

    //n要素で初期化
    void init(int n){
        par.resize(n);
        siz.resize(n);
        for(int i = 0; i < n; i++){
            par[i] = i;
            siz[i] = 1;
        }
    }

    //木の根を求める
    int root(int x){
        if(par[x] == x) return x;
        else return par[x] = root(par[x]);
    }

    //xとyの属する集合を併合
    void unite(int x, int y){
        x = root(x);
        y = root(y);
        if(x == y) return;
        if(siz[x] < siz[y]) swap(x, y);
        siz[x] += siz[y];
        par[y] = x;
    }

    bool same(int x, int y){
        return root(x) == root(y);
    }

    int size(int x){
        return siz[root(x)];
    }
};

int dx[2] = {1, 0}, dy[2] = {0, 1};

signed main(){
    int h,w,sx,sy,gx,gy;
    cin >> h >> w;
    cin >> sx >> sy >> gx >> gy;
    sx--;
    sy--;
    gx--;
    gy--;
    string b[h];
    REP(i,h){
        cin >> b[i];
    }
    int c[h][w];
    REP(i,h){
        REP(j,w){
            c[i][j] = b[i][j] - '0';
        }
    }
    int cnt = 0;
    int n[h][w];
    REP(i,h){
        REP(j,w){
            n[i][j] = cnt;
            cnt++;
        }
    }
    UnionFind uf(cnt);
    REP(i,h){
        REP(j,w){
            REP(k,2){
                if(i + dx[k] < h && j + dy[k] < w && c[i][j] - 1 <= c[i + dx[k]][j + dy[k]] && c[i + dx[k]][j + dy[k]] <= c[i][j] + 1){
                    uf.unite(n[i][j], n[i + dx[k]][j + dy[k]]);
                }
                if(i + 2 * dx[k] < h && j + 2 * dy[k] < w && c[i][j] == c[i + 2 * dx[k]][j + 2 * dy[k]] && c[i + dx[k]][j + dy[k]] < c[i][j]){
                    uf.unite(n[i][j], n[i + 2 * dx[k]][j + 2 * dy[k]]);
                }
            }
        }
    }
    if(uf.same(n[sx][sy], n[gx][gy])){
        cout << "YES" << endl;
    }else{
        cout << "NO" << endl;
    }
}