#include "bits/stdc++.h"
using namespace std;
#define int long long
#define FOR(i, a, b) for(int i=(a);i<(b);i++)
#define RFOR(i, a, b) for(int i=(b-1);i>=(a);i--)
#define REP(i, n) for(int i=0; i<(n); i++)
#define RREP(i, n) for(int i=(n-1); i>=0; i--)
#define REP1(i, n) for(int i=1; i<=(n); i++)
#define RREP1(i, n) for(int i=(n); i>=1; i--)
#define ALL(a) (a).begin(),(a).end()
#define UNIQUE_SORT(l) sort(ALL(l)); l.erase(unique(ALL(l)), l.end());
#define CONTAIN(a, b) find(ALL(a), (b)) != (a).end()
#define out(...) printf(__VA_ARGS__)

int dxy[] = {0, 1, 0, -1, 0};

void solve();
signed main()
{
#if DEBUG
    std::ifstream in("input.txt");
    std::cin.rdbuf(in.rdbuf());
#endif
    cin.tie(0);
    ios::sync_with_stdio(false);
    solve();
    return 0;
}

/*================================*/
#if DEBUG
#define SIZE 10
#else
#define SIZE 50
#endif

int H,W;
int S[2], G[2];
vector<string> M;
int DP[SIZE][SIZE];
typedef pair<int,int> pos;

void solve() {
    cin>>H>>W;
    REP(i,2)cin>>S[i], S[i]--;
    REP(i,2)cin>>G[i], G[i]--;
    string s;
    REP(h, H) {
        cin>>s;
        M.push_back(s);
    }
    queue<pos> que;
    que.push(*new pos(S[0], S[1]));
    DP[S[0]][S[1]] = 1;
    while(que.size()) {
        auto p = que.front();
        que.pop();
        int c = M[p.first][p.second]-'0';
        REP(i,4) {
            int nh = p.first + dxy[i];
            int nw = p.second + dxy[i+1];
            if (nh<0||nw<0||nh>=H||nw>=W) continue;
            if (DP[nh][nw]) continue;
            int n = M[nh][nw]-'0';
            if (abs(n-c) <= 1) {
                DP[nh][nw] = 1;
                que.push(*new pos(nh,nw));
            }
        }
        REP(i,4) {
            int nh = p.first + dxy[i]*2;
            int nw = p.second + dxy[i+1]*2;
            if (nh<0||nw<0||nh>=H||nw>=W) continue;
            if (DP[nh][nw]) continue;
            int n = M[nh][nw]-'0';
            int b = M[(nh+p.first)/2][(nw+p.second)/2]-'0';
            if (c==n && b<c) {
                DP[nh][nw] = 1;
                que.push(*new pos(nh,nw));
            }
        }
    }
    
    
    cout << (DP[G[0]][G[1]] ? "YES" : "NO") << endl;
}