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 ww = w + 2;
		boolean[][] field = new boolean[h + 2][w + 2];
		for (int i = 1; i <= h; i++) {
		    for (int j = 1; j <= w; j++) {
		        field[i][j] = sc.nextInt() == 1;
		    }
		}
		ArrayDeque<Integer> deq = new ArrayDeque<>();
		int count = 0;
		for (int i = 1; i <= h; i++) {
		    for (int j = 1; j <= w; j++) {
		        if (field[i][j]) {
		            count++;
		            deq.add(i * ww + j);
		            while (deq.size() > 0) {
		                int x = deq.poll();
		                if (field[x / ww][x % ww]) {
		                    field[x / ww][x % ww] = false;
		                    deq.add(x - 1);
		                    deq.add(x + 1);
		                    deq.add(x + ww);
		                    deq.add(x - ww);
		                }
		            }
		        }
		    }
		}
		System.out.println(count);
    }
}