import java.util.*;

public class Main {
  static int[] par;
  static int[] rank;
  static int[] height;
  static int h;
  static int w;
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    h = sc.nextInt();
    w = sc.nextInt();
    par = new int[h * w];
    rank = new int[h * w];
    height = new int[h * w];

    int sx = sc.nextInt();
    int sy = sc.nextInt();
    int gx = sc.nextInt();
    int gy = sc.nextInt();
    init(h * w);
    for(int i = 0; i < h; i++) {
      String b = sc.next();
      for(int j = 0; j < w; j++) {
        height[w * i + j] = Integer.parseInt(String.valueOf(b.charAt(j)));
      }
    }
    for(int i = 0; i < h * w; i++) {
      if((i - w) >= 0) unite((i - w), i);
      if((i + w) < (h * w)) unite((i + w), i);
      if((i - 1) >= 0) unite((i - 1), i);
      if((i + 1) < (h * w)) unite((i + 1), i);

      if((i - (2 * w)) >= 0) unite((i - (2 * w)), i);
      if((i + (2 * w)) < (h * w)) unite((i + (2 * w)), i);
      if((i - 2) >= 0) unite((i - 2), i);
      if((i + 2) < (h * w)) unite((i + 2), i);
    }
    String ans = "YES";
    if(!same(((w * (sx - 1)) + sy - 1), ((w * (gx - 1)) + gy - 1))) ans = "NO";
    System.out.println(ans);
  }
  static void init(int m) {
      for(int i = 0; i < m; i++) {
        par[i] = i;
        rank[i] = 0;
      }
    }
  static int find(int x) {
      if(par[x] == x) {
        return x;
      } else {
        return par[x] = find(par[x]);
      }
    }
  static void unite(int x, int y) {
      if(find(x) != find(y)) {
      if((Math.abs(x - y) == 1) || (Math.abs(x - y) == w)) {
        if(Math.abs(height[x] - height[y]) <= 1) {
            int x1 = find(x);
            int y1 = find(y);
          if(rank[x1] > rank[y1]) {
            par[y1] = x1;
            rank[x1] += rank[y1];
          } else {
            par[x1] = y1;
            if(rank[x1] == rank[y1]) {
              rank[y1]++;
            } else {
              par[x1] = y1;
              rank[y1] += rank[x1];
            }
          }
        }
      }
      if((Math.abs(x - y) == 2) || (Math.abs(x - y) == (2 * w))) {
        if((x - y) == 2) {
          if((height[x] == height[y]) && (height[x] > height[x - 1])) {
            int x1 = find(x);
            int y1 = find(y);
          if(rank[x1] > rank[y1]) {
            par[y1] = x1;
            rank[x1] += rank[y1];
          } else {
            par[x1] = y1;
            if(rank[x1] == rank[y1]) {
              rank[y1]++;
            } else {
              par[x1] = y1;
              rank[y1] += rank[x1];
            }
          }
          }
        }
        if((x - y) == (-1) * 2) {
          if((height[x] == height[y]) && (height[x] > height[x + 1])) {
            int x1 = find(x);
            int y1 = find(y);
          if(rank[x1] > rank[y1]) {
            par[y1] = x1;
            rank[x1] += rank[y1];
          } else {
            par[x1] = y1;
            if(rank[x1] == rank[y1]) {
              rank[y1]++;
            } else {
              par[x1] = y1;
              rank[y1] += rank[x1];
            }
          }
          }
        }
        if((x - y) == 2 * w) {
          if((height[x] == height[y]) && (height[x] > height[x - w])) {
            int x1 = find(x);
            int y1 = find(y);
          if(rank[x1] > rank[y1]) {
            par[y1] = x1;
            rank[x1] += rank[y1];
          } else {
            par[x1] = y1;
            if(rank[x1] == rank[y1]) {
              rank[y1]++;
            } else {
              par[x1] = y1;
              rank[y1] += rank[x1];
            }
          }
          }
        }
        if((x - y) == (-1) * 2 * w) {
          if((height[x] == height[y]) && (height[x] > height[x + w])) {
            int x1 = find(x);
            int y1 = find(y);
          if(rank[x1] > rank[y1]) {
            par[y1] = x1;
            rank[x1] += rank[y1];
          } else {
            par[x1] = y1;
            if(rank[x1] == rank[y1]) {
              rank[y1]++;
            } else {
              par[x1] = y1;
              rank[y1] += rank[x1];
            }
          }
          }
        }
      }
      }
    }
  static boolean same(int x, int y) {
      return find(x) == find(y);
    }
}