import java.util.*;

public class No697{

	static int H, W;
	static int[][] a;
	static int[] dx = {0, 1, 0, -1};
	static int[] dy = {-1, 0, 1, 0};
		
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

		H = sc.nextInt();
		W = sc.nextInt();

		a = new int[H][W];
		for(int h = 0; h < H; h++){
			for(int w = 0; w < W; w++){
				a[h][w] = sc.nextInt();
			}
		}

		int ans = 0;
		for(int h = 0; h < H; h++){
			for(int w = 0; w < W; w++){
				if(a[h][w] == 1){
					search(h, w);
					ans++;
				}
			}
		}
		System.out.println(ans);
	}
	private static void search(int h, int w){
		a[h][w] = 0;
		for(int i = 0; i < 4; i++){
			int x = w+dx[i], y = h+dy[i];
			if(x >= 0 && x < W && y >= 0 && y < H && a[y][x] == 1){
				search(y, x);
			}
		}
	}
}