#include <iostream>
#include <vector>
#include <utility>
#include <set>
#include <list>
#include <cassert>
#include <queue>
#include <cmath>

using namespace std;
using ll = long long int;
#define REP(i, n) for(int i = 0; i < (int)(n); i++)
#define YES(n) std::cout << ((n) ? "YES" : "NO"  ) << "\n";
#define Yes(n) std::cout << ((n) ? "Yes" : "No" ) << "\n";

#define ALL_INCLUDED_ENVIRONMENT

template <class T, class Alloc, template <class, class> class C> std::ostream& operator<<(std::ostream& o, const C<T, Alloc>& v) {
  o << "{";
  bool init = 1;
  for (auto e : v) {
    if (init) { init = 0; }
    else { o << ", "; }
    o << e;
  }
  o << "}";
  return o;
}

template <class X, class Y> std::ostream& operator<<(std::ostream& o, const std::pair<X, Y>& p) {
  o << "(" << p.first << ", " << p.second << ")";
  return o;
}

ll h, w, sx, sy, gx, gy;
vector<vector<ll> > bs;
queue<pair<ll, ll>> que;
vector<vector<bool> > visited;

void step(ll x, ll y, ll newx, ll newy) {
  if (newx >= 0 && newx < h && newy >= 0 && newy < w
      && abs(bs[x][y] - bs[newx][newy]) <= 1
      && visited[newx][newy] == 0) {
    visited[newx][newy] = 1;
    que.push(make_pair(newx, newy));
  }
}

void jump(ll x, ll y, ll newx, ll newy) {
  ll midx = (x + newx)/2;
  ll midy = (y + newy)/2;
  if (newx >= 0 && newx < h && newy >= 0 && newy < w
      && bs[x][y] == bs[newx][newy]
      && bs[midx][midy] < bs[x][y]
      && visited[newx][newy] == 0) {
    visited[newx][newy] = 1;
    que.push(make_pair(newx, newy));
  }
}

int main() {
  // cin.tie(0);
  // ios::sync_with_stdio(false);
  cin >> h >> w >> sx >> sy >> gx >> gy; cin.ignore();
  sx--; sy--; gx--; gy--;
  bs = vector<vector<ll> >(h, vector<ll>(w, 0));
  visited = vector<vector<bool> >(h, vector<bool>(w, 0));
  visited[sx][sy] = 1;
  que.push(make_pair(sx, sy));
  string line;
  REP (i, h) {
    getline(cin, line);
    REP (j, w) {
      assert('0' <= line[j] && line[j] <= '9');
      bs[i][j] = line[j]-'0';
    }
  }

  while (!que.empty()) {
    pair<ll, ll> node = que.front();
    ll x = node.first;
    ll y = node.second;
    que.pop();
    step(x, y, x-1, y);
    step(x, y, x+1, y);
    step(x, y, x, y-1);
    step(x, y, x, y+1);
    jump(x, y, x-2, y);
    jump(x, y, x+2, y);
    jump(x, y, x, y-2);
    jump(x, y, x, y+2);
  }

  YES(visited[gx][gy]);
  return 0;
}