import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        int H = sc.nextInt();
        int W = sc.nextInt();
        int sx = sc.nextInt()-1;
        int sy = sc.nextInt()-1;
        int gx = sc.nextInt()-1;
        int gy = sc.nextInt()-1;
        int [][] Hight = new int [H][W];
        int [][] dist = new int [H][W];
        for(int i=0; i<H; i++){
            String tmp = sc.next();
            for(int j=0; j<W; j++){
                Hight[i][j] = tmp.charAt(j)-'0';
                dist[i][j] = -1;
            }
        }
        Queue<Integer> q = new LinkedList<>();
        int [] dx = {1,0,-1,0};
        int [] dy = {0,1,0,-1};
        q.add(sx);
        q.add(sy);
        dist[sx][sy]=0;
        while(!q.isEmpty()){
            int x = q.poll();
            int y = q.poll();
            if(x==gx&&y==gy){
                System.out.println("YES");
                return;
            }
            for(int k=1; k<=2; k++){
                for(int i=0; i<4; i++){
                    int nx = x+k*dx[i];
                    int ny = y+k*dy[i];
                    if(nx<0||ny<0||nx>=H||ny>=W)continue;
                    if(dist[nx][ny]!=-1)continue;
                    if( (k==1&&Math.abs(Hight[nx][ny]-Hight[x][y])<=1)||(k==2&&Math.abs(Hight[nx][ny]-Hight[x][y])==0) ){
                        dist[nx][ny]=dist[x][y]+1;
                        q.add(nx);
                        q.add(ny);
                    }
                }
            }
        }
        System.out.println("NO");
    }
}