#include <bits/stdc++.h>
using namespace std;
struct cww{cww(){ios::sync_with_stdio(false);cin.tie(0);}}star;
#define all(c) (c).begin(), (c).end()
#define rall(c) (c).rbegin(), (c).rend()
#define vv(type, c, m, n, i) vector<vector<type>> c(m, vector<type>(n, 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##_len=(n); i>i##_len; --i)
#define len(x) ((int)(x).size())
#define mp make_pair
#define eb emplace_back
#define em emplace
#define pb pop_back
#define fi first
#define se second
#define get(a, i) get<i>(a)
#define mt make_tuple
typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<double> vd;
typedef vector<long long> vll;
typedef vector<string> vs;
typedef vector<bool> vb;
typedef pair<int, int> pii;
#define mini min_element
#define maxi max_element
#define sum(a, b) accumulate(a, b)
#define chmax(a,b) if(a<b)a=b
#define chmin(a,b) if(a>b)a=b
#define ce(x, y) (x + y - 1) / y
#define print(t) cout << (t) << "\n";
#define printk(v) {rep(i, 0, len(v) - 1) { cout << v[i] << " "; } cout << v.back() << endl;}
constexpr int dx[] = {1, 0, -1,  0};
constexpr int dy[] = {0, 1,  0, -1};
string solve() {
	int h, w; cin >> h >> w;
	vv(bool, b, h, w, false);
	vv(int, v, h, w, 0);
	int sy, sx, gy, gx; cin >> sy>> sx >> gy >> gx;
	if (sy == gy && sx == gx) return "YES";
	--sy; --sx; --gy; --gx;
	string s;
	rep(i, 0, h) {
		cin >> s;
		rep(j, 0, w) {
			v[i][j] = s[j] - '0';
		}
	}
	vector<tuple<int, int>> dp = {tie(sy, sx)};
	b[sy][sx] = true;
	int y, x, ny, nx;
	while (!dp.empty()) {
		tie(y, x) = dp.back(); dp.pb();
		rep(i, 0, 4) {
			ny = y + dy[i];
			nx = x + dx[i];
			if (!(0 <= ny && ny < h && 0 <= nx && nx < w)) continue;
			if (!b[ny][nx] && abs(v[ny][nx] - v[y][x]) <= 1) {
				if (ny == gy && nx == gx)
					return "YES";
				b[ny][nx] = true;
				dp.eb(tie(ny, nx));
			}
			if (v[ny][nx] >= v[y][x]) continue;
			ny += dy[i];
			nx += dx[i];
			if (!(0 <= ny && ny < h && 0 <= nx && nx < w)) continue;
			if (!b[ny][nx] && v[ny][nx] == v[y][x]) {
				if (ny == gy && nx == gx)
					return "YES";
				b[ny][nx] = true;
				dp.eb(tie(ny, nx));
			}
		}
	}
	return "NO";
}
int main() {
	print(solve());
	return 0;
}