#include <iostream>
#include <queue>
#include <utility>
using namespace std;

using P = pair<int, int>;

const int MAX_H = 60;
const int MAX_W = 60;

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

string b[MAX_H];

bool visited[MAX_H][MAX_W];
int h, w, sx, sy, gx, gy;

bool inside(int x, int y) {
    return 0 <= x && x < h && 0 <= y && y < w;
}

int main() {
    cin >> h >> w;
    cin >> sx >> sy >> gx >> gy;
    sx--; sy--;
    gx--; gy--;

    for (int i = 0; i < h; i++) {
        cin >> b[i];
    }


    queue<P> que;
    que.push(P(sx, sy));
    visited[sx][sy] = true;
    while (!que.empty()) {
        P p = que.front(); que.pop();
        if (p.first == gx && p.second == gy) {
            cout << "YES" << endl;
            return 0;
        }
        int x = p.first,
            y = p.second;
        for (int i = 0; i < 4; i++) {
            for (int d = 1; d <= 2; d++) {
                int nx = x + dx[i] * d,
                    ny = y + dy[i] * d;
                if (!inside(nx, ny) || visited[nx][ny]) continue;

                if (d == 1 && abs((b[x][y] - '0') - (b[nx][ny] - '0')) <= 1) {
                    que.push(P(nx, ny));
                    visited[nx][ny] = true;
                }
                if (d == 2 && abs((b[x][y] - '0') - (b[nx][ny] - '0')) == 0
                        && b[x][y] - '0' > b[x + dx[i]][y + dy[i]] - '0') {
                    que.push(P(nx, ny));
                    visited[nx][ny] = true;
                }
            }
        }
    }
    cout << "NO" << endl;

    return 0;
}