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

// 基本テンプレート
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
#define P(x) cout << (x) << endl
#define p(x) cout << (x)
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define mat(type, c, m, n) vector<vector<type>> c(m, vector<type>(n));for(auto& r:c)for(auto& i:r)cin>>i;
#define rep(i,a,n) for(int i=(a), i##_len=(n); i<i##_len; ++i)
#define rrep(i,a,n) for(int i=(a); i>n; --i)
#define each(x,y) for(auto &(x):(y))
#define perm(c) sort(all(c));for(bool c##p=1;c##p;c##p=next_permutation(all(c)))
#define cauto const auto&
#define UNIQUE(v) v.erase( unique(all(v)), v.end() );
#define len(x) ((int)(x).size())
#define length(a)   (sizeof(a)/sizeof(a[0]))
inline void print() {cout << endl;}
template <class H, class... T> inline void print(H h, T... t){cout << h << " ";print(t...);}
#define dbg(v) for(auto i : v) cout << i << " "; cout << endl;

// 型
typedef long long ll;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<long long> vll;
typedef vector<string> vs;

ll mod = (int)1e9 + 7;

// 定数
#define PI acos(-1.0)
//constexpr int EPS = (1e-9);
//constexpr int INF = 100000000;

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


// 8近傍
//constexpr int dy[]={0,0,1,-1,1,1,-1,-1};
//constexpr int dx[]={1,-1,0,0,1,-1,1,-1};

//constexpr int MAX = 1005;
int h, w;
inline bool out_of_stage(int r, int c) {
	return r < 0 || r >= h || c < 0 || c >= w;
}

inline bool bfs(int h, int w, pair<int, int> start, pair<int, int> goal, vs stage) {
	map<pair<int, int>, bool> visited;
	visited[start] = true;
	deque<pair<int, int>> q;
	q.push_back(start);
	while(!q.empty()) {
		vi r(2);
		int r0, c0; tie(r0, c0) = q.front(); q.pop_front();
		if(make_pair(r0, c0) == goal) return true;
		rep(i, 0, 4) {
			int r = r0 + dx[i];
			int c = c0 + dy[i];
			if(out_of_stage(r, c)) continue;
			if(abs(stage[r][c] - stage[r0][c0]) <= 1 && !visited[make_pair(r, c)]) {
				visited[make_pair(r, c)] = true;
				q.push_back(make_pair(r, c));
			}
			int r2 = r0 + dx[i] * 2;
			int c2 = c0 + dy[i] * 2;
			if(out_of_stage(r2, c2)) continue;
			if(stage[r2][c2] == stage[r0][c0] && stage[r0][c0] > stage[r][c]) {
				if(!visited[make_pair(r2, c2)]) {
					visited[make_pair(r2, c2)] = true;
					q.push_back(make_pair(r2, c2));
				}
			}
		}
	}
	return false;
}



int main() {
//	cout << setprecision(12) << fixed;

	cin >> h >> w;
	int sx, sy, gx, gy; cin >> sx >> sy >> gx >> gy;
	--sx, --sy, --gx, --gy;
	pair<int, int> start = make_pair(sx, sy);
	pair<int, int> goal = make_pair(gx, gy);
	vs stage(h); rep(i, 0, h) cin >> stage[i];
	P(bfs(h, w, start, goal, stage) ? "YES" : "NO");

	return 0;
}