import java.io.*;
import java.util.*;
import java.math.*;
import java.awt.Point;

public class Main {
    InputStream is;
    PrintWriter out;
    String INPUT = "";

    long MOD = 1_000_000_007;
    int inf = 10000000;
    int h,w,sx,sy,gx,gy;
    int[][] b;
    boolean[][] seen;
    void solve()
    {
        h = ni();
        w = ni();
        sx = ni();
        sy = ni();
        gx = ni();
        gy = ni();
        char[][] board = new char[h][];
        b = new int[h][w];
        seen = new boolean[h][w];
        for(int i = 0; i < h; i++){
            board[i] = ns().toCharArray();
            for(int j = 0; j < w; j++){
                b[i][j] = board[i][j] - '0';
            }
        }
        boolean ans = f(sx-1,sy-1);
        out.println(ans ? "YES" : "NO");

    }

    boolean f(int x, int y){
        seen[x][y] = true;
        if(x == gx-1 && y == gy-1){
            return true;
        }
        int[] dx = new int[]{-1,0,1,0};
        int[] dy = new int[]{0,-1,0,1};
        boolean res = false;
        for(int i = 0; i < 4; i++){
            int tx = x + dx[i];
            int ty = y + dy[i];
            int tx2 = x + 2*dx[i];
            int ty2 = y + 2*dy[i];
            if(tx >= 0 && tx <= h-1 && ty >= 0 && ty <= w-1 && !seen[tx][ty]){
                if(Math.abs(b[tx][ty]-b[x][y]) <= 1) res |= f(tx,ty);
            }
            if(tx2 >= 0 && tx2 <= h-1 && ty2 >= 0 && ty2 <= w-1 && !seen[tx2][ty2]){
                if(b[tx2][ty2] == b[x][y] && b[tx][ty] < b[x][y]) res |= f(tx2,ty2);
            }
        }
        return res;
    }

    void run() throws Exception
    {
        is = INPUT.isEmpty() ? System.in : new ByteArrayInputStream(INPUT.getBytes());
        out = new PrintWriter(System.out);
        
        long s = System.currentTimeMillis();
        solve();
        out.flush();
        if(!INPUT.isEmpty())tr(System.currentTimeMillis()-s+"ms");
    }
    
    public static void main(String[] args) throws Exception { new Main().run(); }
    
    private byte[] inbuf = new byte[1024];
    private int lenbuf = 0, ptrbuf = 0;
    
    private int readByte()
    {
        if(lenbuf == -1)throw new InputMismatchException();
        if(ptrbuf >= lenbuf){
            ptrbuf = 0;
            try { lenbuf = is.read(inbuf); } catch (IOException e) { throw new InputMismatchException(); }
            if(lenbuf <= 0)return -1;
        }
        return inbuf[ptrbuf++];
    }
    
    private boolean isSpaceChar(int c) { return !(c >= 33 && c <= 126); }
    private int skip() { int b; while((b = readByte()) != -1 && isSpaceChar(b)); return b; }
    
    private double nd() { return Double.parseDouble(ns()); }
    private char nc() { return (char)skip(); }
    
    private String ns()
    {
        int b = skip();
        StringBuilder sb = new StringBuilder();
        while(!(isSpaceChar(b) && b != ' ')){
            sb.appendCodePoint(b);
            b = readByte();
        }
        return sb.toString();
    }
    
    private char[] ns(int n)
    {
        char[] buf = new char[n];
        int b = skip(), p = 0;
        while(p < n && !(isSpaceChar(b))){
            buf[p++] = (char)b;
            b = readByte();
        }
        return n == p ? buf : Arrays.copyOf(buf, p);
    }
    
    private char[][] nm(int n, int m)
    {
        char[][] map = new char[n][];
        for(int i = 0;i < n;i++)map[i] = ns(m);
        return map;
    }
    
    private int[] na(int n)
    {
        int[] a = new int[n];
        for(int i = 0;i < n;i++)a[i] = ni();
        return a;
    }
    
    private int ni()
    {
        int num = 0, b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private long nl()
    {
        long num = 0;
        int b;
        boolean minus = false;
        while((b = readByte()) != -1 && !((b >= '0' && b <= '9') || b == '-'));
        if(b == '-'){
            minus = true;
            b = readByte();
        }
        
        while(true){
            if(b >= '0' && b <= '9'){
                num = num * 10 + (b - '0');
            }else{
                return minus ? -num : num;
            }
            b = readByte();
        }
    }
    
    private static void tr(Object... o) { System.out.println(Arrays.deepToString(o)); }

    static class ArrayUtils {
        public static void fill(double[][] array, double value) {
            for (double[] a : array) Arrays.fill(a, value);
        }
 
        public static void fill(double[][][] array, double value) {
            for (double[][] l : array) fill(l, value);
        } 
    }
}