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

#define REP(i,n) for(int i=0;i<n;i++)
#define rep(i,n) for(int i=0;i<n;i++)
#define INF 1<<29
#define LINF LLONG_MAX/3
#define MP make_pair
#define PB push_back
#define EB emplace_back
#define ALL(v) (v).begin(),(v).end()
#define debug(x) cerr<<#x<<":"<<x<<endl
#define debug2(x,y) cerr<<#x<<","<<#y":"<<x<<","<<y<<endl
#define CININIT cin.tie(0),ios::sync_with_stdio(false)
template<typename T> ostream& operator<<(ostream& os,const vector<T>& vec){ os << "["; for(const auto& v : vec){ os << v << ","; } os << "]"; return os; }

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int,int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;

bool vis[64][64];
int maze[64][64];
int h,w;

const int dx[]={0,1,0,-1} , dy[]={1,0,-1,0};

bool ok(int x,int y){
    return (x>=0 and x<h and y>=0 and y<w);
}

int main(){
    cin>>h>>w;
    int sx,sy,gx,gy;
    cin>>sx>>sy>>gx>>gy;
    sx--;
    sy--;
    gx--;
    gy--;
    rep(i,h){
        string s;cin>>s;
        for(int j=0;j<w;j++){
            maze[i][j]=s[j]-'0';
        }
    }

    vis[sx][sy]=true;

    queue<pii> que;
    que.push(pii(sx,sy));
    while(!que.empty()){
        auto p = que.front();
        que.pop();
        int x = p.first;
        int y = p.second;
//        cout << "pop : (" << x << "," << y << ")" << endl;
        if(x==gx and y==gy){
            cout << "YES" << endl;
            return 0;
        }

        for(int i=0;i<4;i++){
            int nx=x+dx[i];
            int ny=y+dy[i];
            if(!ok(nx,ny)) continue;
            if(vis[nx][ny]) continue;
            if(abs(maze[nx][ny]-maze[x][y])<=1){
                vis[nx][ny]=true;
//                cout << "push: (" << nx << "," << ny << ")" << endl;
                que.push(pii(nx,ny));
            }
        }

        for(int i=0;i<4;i++){
            int nx=x+2*dx[i];
            int ny=y+2*dy[i];

            if(!ok(nx,ny)) continue;
            if(vis[nx][ny]) continue;

            if(maze[nx][ny]==maze[x][y] and maze[x+dx[i]][y+dy[i]]<maze[x][y]){
                vis[nx][ny]=true;
                que.push(pii(nx,ny));
//                cout << "push: (" << nx << "," << ny << ")" << endl;
            }
        }
    }
    cout << "NO" << endl;
}