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

using vi = vector<int>; using vvi = vector<vi>; using vvvi = vector<vvi>;
using ll = long long int;
using vll = vector<ll>; using vvll = vector<vll>; using vvvll = vector<vvll>;
using vd = vector<double>; using vvd = vector<vd>; using vvvd = vector<vvd>;
using P = pair<int, int>;
using Pll = pair<ll, ll>;
using cdouble = complex<double>;

const double eps = 1e-9;
const double INFD = numeric_limits<double>::infinity();
const double PI = 3.14159265358979323846;
#define Loop(i, n) for(int i = 0; i < (int)n; i++)
#define Loopll(i, n) for(ll i = 0; i < (ll)n; i++)
#define Loop1(i, n) for(int i = 1; i <= (int)n; i++)
#define Loopll1(i, n) for(ll i = 1; i <= (ll)n; i++)
#define Loopr(i, n) for(int i = (int)n - 1; i >= 0; i--)
#define Looprll(i, n) for(ll i = (ll)n - 1; i >= 0; i--)
#define Loopr1(i, n) for(int i = (int)n; i >= 1; i--)
#define Looprll1(i, n) for(ll i = (ll)n; i >= 1; i--)
#define Foreach(buf, container) for(auto buf : container)
#define Loopdiag(i, j, h, w, sum) for(int i = ((sum) >= (h) ? (h) - 1 : (sum)), j = (sum) - i; i >= 0 && j < (w); i--, j++)
#define Loopdiagr(i, j, h, w, sum) for(int j = ((sum) >= (w) ? (w) - 1 : (sum)), i = (sum) - j; j >= 0 && i < (h); j--, i++)
#define Loopdiagsym(i, j, h, w, gap) for (int i = ((gap) >= 0 ? (gap) : 0), j = i - (gap); i < (h) && j < (w); i++, j++)
#define Loopdiagsymr(i, j, h, w, gap) for (int i = ((gap) > (h) - (w) - 1 ? (h) - 1 : (w) - 1 + (gap)), j = i - (gap); i >= 0 && j >= 0; i--, j--)
#define Loopitr(itr, container) for(auto itr = container.begin(); itr != container.end(); itr++)
#define printv(vector) Loop(ex_i, vector.size()) { cout << vector[ex_i] << " "; } cout << endl;
#define printmx(matrix) Loop(ex_i, matrix.size()) { Loop(ex_j, matrix[ex_i].size()) { cout << matrix[ex_i][ex_j] << " "; } cout << endl; }
#define quickio() ios::sync_with_stdio(false); cin.tie(0);
#define bitmanip(m,val) static_cast<bitset<(int)m>>(val)
#define Comp(type_t) bool operator<(const type_t &another) const
#define fst first
#define snd second
bool nearlyeq(double x, double y) { return abs(x - y) < eps; }
bool inrange(int x, int t) { return x >= 0 && x < t; }
bool inrange(vi xs, int t) { Foreach(x, xs) if (!(x >= 0 && x < t)) return false; return true; }
ll rndf(double x) { return (ll)(x + (x >= 0 ? 0.5 : -0.5)); }
ll floorsqrt(ll x) { ll m = (ll)sqrt((double)x); return m + (m * m <= x ? 0 : -1); }
ll ceilsqrt(ll x) { ll m = (ll)sqrt((double)x); return m + (x <= m * m ? 0 : 1); }
ll rnddiv(ll a, ll b) { return (a / b + (a % b * 2 >= b ? 1 : 0)); }
ll ceildiv(ll a, ll b) { return (a / b + (a % b == 0 ? 0 : 1)); }
ll gcd(ll m, ll n) { if (n == 0) return m; else return gcd(n, m % n); }
ll lcm(ll m, ll n) { return m * n / gcd(m, n); }

/*******************************************************/



int main() {
	int n, m; cin >> n >> m;
	int si, sj, ti, tj;
	cin >> si >> sj >> ti >> tj;
	si--; sj--; ti--; tj--;
	vvi board(n, vi(m));
	Loop(i, n) {
		string s; cin >> s;
		Loop(j, m) {
			board[i][j] = s[j] - '0';
		}
	}
	vi di = { 0,0,-1,1 };
	vi dj = { -1,1,0,0 };
	vi di2 = { 0,0,-2,2 };
	vi dj2 = { -2,2,0,0 };
	vvi able(n, vi(m));
	stack<P> stk;
	able[si][sj] = 1;
	stk.push({ si, sj });
	while (stk.size()) {
		int xi = stk.top().fst;
		int xj = stk.top().snd;
		stk.pop();
		Loop(k, 4) {
			int yi = xi + di[k];
			int yj = xj + dj[k];
			if (inrange(yi, n) && inrange(yj, m)) {
				if (abs(board[yi][yj] - board[xi][xj]) <= 1) {
					if (!able[yi][yj]) {
						able[yi][yj] = 1;
						stk.push({ yi,yj });
					}
				}
			}
		}
		Loop(k, 4) {
			int yi = xi + di2[k];
			int yj = xj + dj2[k];
			int zi = xi + di[k];
			int zj = xj + dj[k];
			if (inrange(yi, n) && inrange(yj, m)) {
				if (abs(board[yi][yj] - board[xi][xj]) == 0
					&& board[xi][xj] > board[zi][zj]) {
					if (!able[yi][yj]) {
						able[yi][yj] = 1;
						stk.push({ yi,yj });
					}
				}
			}
		}
	}
	if (able[ti][tj]) cout << "YES" << endl;
	else cout << "NO" << endl;
}