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

#define rep(i,n) for(long long i = 0; i < (long long)(n); i++)
using ll = long long; using vll = vector<ll>; using vvll = vector<vll>;

struct UnionFind {
    vector<int> data;
    UnionFind(int size) : data(size, -1) { }
    // x, yをマージ
    bool unite(int x, int y) {
        x = root(x); y = root(y);
        if (x != y) {
            if (data[y] < data[x]) swap(x, y);
            data[x] += data[y]; data[y] = x;
        }
        return x != y;
    }
    // x, yが同じ集合なら1
    bool find(int x, int y) {
        return root(x) == root(y);
    }
    // xの根を探す。同じ集合なら同じ根が帰る
    int root(int x) {
        return data[x] < 0 ? x : data[x] = root(data[x]);
    }
};

#define get(i, j) (b[i+buff/2][j+buff/2])
#define encode(i, j) (i*w+j)
int main(void) {
    cin.tie(0); ios::sync_with_stdio(false);
    ll h, w; cin >> h >> w;
    ll sx, sy, gx, gy; cin >> sx >> sy >> gx >> gy;
    sx--; sy--; gx--; gy--;

    const int buff = 10;
    vvll b(h+buff, vll(w+buff, -5));
    rep(i, h) {
        string s; cin >> s;
        rep(j, s.length()) {
            get(i, j) = s[j] - '0';
        }
    }

    vll di = {1, -1, 0, 0};
    vll dj = {0, 0, 1, -1};
    UnionFind uf(h*w);
    rep(i, h) {
        rep(j, w) {
            rep(d, 4) {
                ll nexti = i + di[d];
                ll nextj = j + dj[d];
                if (abs(get(i, j) - get(nexti, nextj)) <= 1)
                    uf.unite(encode(i, j), encode(nexti, nextj));
            }
            rep(d, 4) {
                ll nexti = i + di[d] * 2;
                ll nextj = j + dj[d] * 2;
                if (get(i, j) == get(nexti, nextj) && get(i, j) > get(i + di[d], j + dj[d]))
                    uf.unite(encode(i, j), encode(nexti, nextj));
            }
        }
    }

    if (uf.find(encode(sx, sy), encode(gx, gy))) {
        cout << "YES" << endl;
    } else {
        cout << "NO" << endl;
    }

    return 0;
}