#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <utility>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <functional>

using namespace std;

#define int long long

#define fst first
#define scd second
#define PB push_back
#define MP make_pair
#define all(a) a.begin(),a.end()
#define rall(a) a.rbegin(),a.rend()
#define omajinai ios::sync_with_stdio(false);cin.tie(0)
#define rep(i,x) for(int i=0;i<(int)(x);++i)
#define rep1(i,x) for(int i=1;i<=(int)(x);++i)

typedef long long ll;
typedef long double ld;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef pair<int, int> pii;
typedef vector<pii> vpii;

template<typename T>T& max(T&a,T&b){if(a>=b)return a;return b;}
template<typename T>T& min(T&a,T&b){if(a<b)return a;return b;}
template<typename T>bool chmax(T&a,T b){if(a<b){a=b;return true;}return false;}
template<typename T>bool chmin(T&a,T b){if(a>b){a=b;return true;}return false;}
template<typename T>T get(){T a;cin>>a;return a;}
template<typename T>T rev(T a){reverse(all(a));return a;}
template<typename T>vector<T>&sort(vector<T>&a){sort(all(a));return a;}

const int inf = 1e9;
const ll linf = 3e18;
const double eps = 1e-9;

int H, W;
int mp[55][55];
bool visited[55][55];

int dy1[4] = {-1, 0, 1, 0};
int dx1[4] = {0, -1, 0, 1};
int dy2[4] = {-2, 0, 2, 0};
int dx2[4] = {0, -2, 0, 2};

bool inside(int y, int x)
{
    return 0 <= y && y < H && 0 <= x && x < W;
}

signed main()
{ // #define int long long をしてるのでscanfを使うと意味不明な値が入力され死にます
    cin >> H >> W;

    int sy, sx; cin >> sy >> sx;
    int gy, gx; cin >> gy >> gx;

    --sy, --sx;
    --gy, --gx;

    rep(i, H) rep(j, W) {
        char c; cin >> c;
        mp[i][j] = c - '0';
    }

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

    while (q.size()) {
        pii p = q.front(); q.pop();

        rep(i, 4) {
            int ny = p.fst + dy1[i];
            int nx = p.scd + dx1[i];
            
            if (!inside(ny, nx)) continue;
            if (visited[ny][nx]) continue;

            if (abs(mp[p.fst][p.scd] - mp[ny][nx]) <= 1) {
                visited[ny][nx] = true;
                q.push(pii(ny, nx));
            }
        }

        rep(i, 4) {
            int ny = p.fst + dy2[i];
            int nx = p.scd + dx2[i];
            
            if (!inside(ny, nx)) continue;
            if (visited[ny][nx]) continue;

            if (mp[p.fst][p.scd] == mp[ny][nx]) {
                bool f = false;

                if (ny < 0) {
                    if (mp[p.fst][p.scd] > mp[ny + 1][nx]) f = true;
                }
                if (ny > 0) {
                    if (mp[p.fst][p.scd] > mp[ny - 1][nx]) f = true;
                }
                if (nx < 0) {
                    if (mp[p.fst][p.scd] > mp[ny][nx + 1]) f = true;
                }
                if (nx > 0) {
                    if (mp[p.fst][p.scd] > mp[ny][nx - 1]) f = true;
                }

                if (f) {
                    visited[ny][nx] = true;
                    q.push(pii(ny, nx));
                }
            }
        }
    }

    cout << (visited[gy][gx] ? "YES" : "NO") << endl;
}