import java.util.*;

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

    int[][] a = new int[h][w];
    for(int i = 0; i < h; i++) {
      for(int j = 0; j < w; j++) {
        a[i][j] = sc.nextInt();
      }
    }
 
    for(int i = 0; i < h; i++) {
      for(int j = 0; j < w; j++) {
        if(a[i][j] == 1) {
          int p = i * w + j;
          if(i > 0) unite(p, p - w);
          if(i < h - 1) unite(p, p + w);
          if(j > 0) unite(p, p - 1);
          if(j < w - 1) unite(p, p + 1);
        }
      }
    }

    HashSet<Integer> set = new HashSet<Integer>();

    for(int i = 0; i < h; i++) {
      for(int j = 0; j < w; j++) {
        if(a[i][j] == 1) {
          set.add(find(i * w + j));
        }
      }
    }

    System.out.println(set.size());
  }
  static void init(int m) {
      for(int i = 0; i < m; i++) {
        par[i] = i;
        rank[i] = 1;
      }
    }
  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) {
      x = find(x);
      y = find(y);
      if(x != y) {
        if(rank[x] < rank[y]) {
          par[x] = y;
        } else {
          par[y] = x;
          if(rank[x] == rank[y]) rank[x]++; 
        }
      }
    }
  static boolean same(int x, int y) {
      return find(x) == find(y);
    }
}