/* package whatever; // don't place package name! */

import java.util.*;
import java.lang.*;
import java.io.*;

/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
    public static void main (String[] args) throws java.lang.Exception
    {
        // your code goes here
        BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
        String[] lines = br.readLine().split(" ");
        int h = Integer.parseInt(lines[0]);
        int w = Integer.parseInt(lines[1]);
        
        lines = br.readLine().split(" ");
        int sh = Integer.parseInt(lines[0])-1;
        int sw = Integer.parseInt(lines[1])-1;
        int gh = Integer.parseInt(lines[2])-1;
        int gw = Integer.parseInt(lines[3])-1;
        
        int[][] map = new int[h][w];
        boolean[][] visit = new boolean[h][w];
        for(int i=0;i<h;i++){
            lines = br.readLine().split("");
            for(int j=0;j<w;j++){
                map[i][j] = Integer.parseInt(lines[j]);
                visit[i][j] = false;
            }
        }
        
        Deque<Pair> deq = new ArrayDeque<Pair>();
        Pair start = new Pair(sh,sw);
        Pair goal  = new Pair(gh,gw);
        deq.add(start);
        visit[sh][sw] = true;
        start:while(!deq.isEmpty()){
            Pair p = deq.removeFirst();
            for(Pair next:getNext(map,p)){
                if(visit[next.h][next.w] == false){
                    visit[next.h][next.w] = true;
                    if(next.equals(goal)){
                        break start;
                    }
                    deq.add(next);
                }
            }
        }
        
        System.out.println(visit[gh][gw]?"YES":"NO");
    }
    
    static private ArrayList<Pair> getNext(int[][] map,Pair p){
        int now_height = map[p.h][p.w];
        ArrayList<Pair> ret = new ArrayList<Pair>();
        
        for(Pair next:Pair.nexts){
            try{
                if(Math.abs(map[p.h+next.h][p.w+next.w] - now_height) <= 1){
                    ret.add(new Pair(p.h+next.h,p.w+next.w));
                }
                if( map[p.h+next.h][p.w+next.w] < now_height
                &&  map[p.h+next.h*2][p.w+next.w*2] == now_height){
                    ret.add(new Pair(p.h+next.h*2,p.w+next.w*2));
                }
            }catch(Exception e){}
        }
        
        return ret;
    }
    
    private static class Pair{
        static Pair[] nexts = new Pair[]{new Pair(1,0),new Pair(0,1),new Pair(-1,0),new Pair(0,-1)};
        public int h;
        public int w;
        public Pair(int h,int w){
            this.h = h;
            this.w = w;
        }
        public boolean equals(Pair p){
            return this.h==p.h && this.w == p.w;
        }
        public String toString(){
            return new StringBuilder().append(h).append(",").append(w).toString();
        }
    }
}