#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using P = pair<int, int>;
using T = tuple<int, int, int>;
#define al(a) a.begin(), a.end()
#define ral(a) a.rbegin(), a.rend()
#define sz(a) (int)a.size()
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rrep(i, n) for (int i = 1; i <= (n); ++i)
#define drep(i, n) for (int i = (n)-1; i >= 0; --i)
#define db(a, b) cout << #a << ": " << a << " " << #b << ": " << b << endl;

//{上,右,下,左}
const int dx[] = {-1, 0, 1, 0}, dy[] = {0, 1, 0, -1};

int main() {
  int h, w;
  cin >> h >> w;
  int sx, sy, tx, ty;
  cin >> sx >> sy >> tx >> ty;
  --sx, --sy, --tx, --ty;
  vector<string> s(h);
  rep(i, h) cin >> s[i];

  queue<P> q;
  const int INF = 1001001001;
  vector dist(h, vector<int>(w, INF));
  auto push = [&](int nx, int ny, int nd) {
    if (nx < 0 || ny < 0 || nx >= h || ny >= w) return;
    if (dist[nx][ny] != INF) return;
    dist[nx][ny] = nd;
    q.emplace(nx, ny);
  };
  push(sx, ty, 0);

  while (sz(q)) {
    auto [x, y] = q.front();
    int high = s[x][y] - '0';
    int d = dist[x][y];
    q.pop();
    rep(i, 4) {
      {
        int nx = dx[i] + x, ny = dy[i] + y;
        if (nx >= 0 && ny >= 0 && nx < h && ny < w) {
          int nh = s[nx][ny] - '0';
          if (high == nh || high + 1 == nh || high - 1 == nh)
            push(nx, ny, d + 1);
        }
      }
      {
        int nx = dx[i] * 2 + x, ny = dy[i] * 2 + y;
        int cx = dx[i] + x, cy = dy[i] + y;
        if (nx >= 0 && ny >= 0 && nx < h && ny < w) {
          //   db(nx, ny);
          //   db((nx < h), h);
          int nh = s[nx][ny] - '0';
          int ch = s[cx][cy] - '0';
          if (high == nh && high > ch) push(nx, ny, d + 1);
        }
      }
    }
  }

  if (dist[tx][ty] != INF)
    cout << "YES" << endl;
  else
    cout << "NO" << endl;
  return 0;
}