using System;
using System.Collections.Generic;

public class Program
{
    static void Main()
    {
        var input = Console.ReadLine().Split(' ');

        var H = int.Parse(input[0]);
        var W = int.Parse(input[1]);
        var A = new bool[H, W];

        for (var i = 0; i < H; i++)
        {
            input = Console.ReadLine().Split();
            for (var j = 0; j < W; j++) A[i, j] = input[j] == "1";
        }

        int[] dx = {0, 1, 0, -1};
        int[] dy = {1, 0, -1, 0};
        int dl = 4;

        var ans = 0;
        var que = new Queue<int>(18000010);

        for (var y = 0; y < H; y++)
        for (var x = 0; x < W; x++)
        {
            if (A[y, x])
            {
                ans++;
                A[y, x] = false;
                que.Enqueue(x);
                que.Enqueue(y);

                while (que.Count > 0)
                {
                    var cx = que.Dequeue();
                    var cy = que.Dequeue();

                    for (var l = 0; l < dl; l++)
                    {
                        var nx = cx + dx[l];
                        var ny = cy + dy[l];

                        if (0 <= nx && nx < W && 0 <= ny && ny < H && A[ny, nx])
                        {
                            A[ny, nx] = false;
                            que.Enqueue(nx);
                            que.Enqueue(ny);
                        }
                    }
                }
            }
        }

        Console.WriteLine(ans);
    }
}