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

#define _p(...) (void)printf(__VA_ARGS__)
#define forr(x,arr) for(auto&& x:arr)
#define _overload3(_1,_2,_3,name,...) name
#define _rep2(i,n) _rep3(i,0,n)
#define _rep3(i,a,b) for(int i=int(a);i<int(b);++i)
#define rep(...) _overload3(__VA_ARGS__,_rep3,_rep2,)(__VA_ARGS__)
#define _rrep2(i,n) _rrep3(i,0,n)
#define _rrep3(i,a,b) for(int i=int(b)-1;i>=int(a);i--)
#define rrep(...) _overload3(__VA_ARGS__,_rrep3,_rrep2,)(__VA_ARGS__)
#define ALL(x) (x).begin(), (x).end()
#define BIT(n) (1LL<<(n))
#define SZ(x) ((int)(x).size())
#define fst first
#define snd second
using ll=long long;using pii=pair<int,int>;using vb=vector<bool>;
using vi=vector<int>;using vvi=vector<vi>;using vvvi=vector<vvi>;
using vl=vector<ll>;using vvl=vector<vl>;using vvvl=vector<vvl>;
using vd=vector<double>;using vvd=vector<vd>;using vvvd=vector<vvd>;
using vpii=vector<pii>;using vvpii=vector<vpii>;using vvvpii=vector<vvpii>;

// R, D, L, U
int DY[4] = {0, 1, -1, 0};
int DX[4] = {1, 0, 0, -1};

template<typename T> bool inside(T y, T x, T h, T w) { return 0 <= y && y < h && 0 <= x && x < w; };

bool Main() {
  int H, W;
  cin >> H >> W;
  int sx, sy, gx, gy;
  cin >> sy >> sx >> gy >> gx;
  sx--; sy--; gx--; gy--;

  vector<string> M(H);
  rep(i, H) cin >> M[i];

  vector<vb> visited(H, vb(W));

  queue<pii> q;
  visited[sy][sx] = 1;
  q.emplace(sy, sx);

  while (!q.empty()) {
    int y, x;
    tie(y, x) = q.front(); q.pop();

    if (y == gy && x == gx) return true;
    int h = M[y][x] - '0';

    rep(i, 4) {
      int ny = y + DY[i];
      int nx = x + DX[i];
      if (!inside(ny, nx, H, W)) continue;
      if (visited[ny][nx]) continue;
      int nh = M[ny][nx] - '0';
      if (abs(h - nh) > 1) continue;
      visited[ny][nx] = 1;
      q.emplace(ny, nx);
    }
    rep(i, 4) {
      int ny = y + DY[i] * 2;
      int nx = x + DX[i] * 2;
      if (!inside(ny, nx, H, W)) continue;
      if (visited[ny][nx]) continue;
      int ah = M[y+DY[i]][x+DX[i]] - '0';
      int nh = M[ny][nx] - '0';
      if (abs(h - nh) > 0) continue;
      if (ah >= h) continue;
      visited[ny][nx] = 1;
      q.emplace(ny, nx);
    }
  }
  return false;
}

int main() {
  cin.tie(0); ios::sync_with_stdio(false);
  puts(Main() ? "YES" : "NO");
  return 0;
}