using System;
using System.Collections.Generic;

namespace No697
{
    public class Program
    {
        void Solve()
        {
            //---------------------------------
            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;
            for (var y = 0; y < H; y++)
            for (var x = 0; x < W; x++)
            {
                if (A[y, x])
                {
                    ans++;
                    var que = new Queue<int>();
                    que.Enqueue(x);
                    que.Enqueue(y);

                    while (que.Count > 0)
                    {
                        var cx = que.Dequeue();
                        var cy = que.Dequeue();
                        A[cy, cx] = false;

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

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

            Console.WriteLine(ans);
            //---------------------------------
        }

        static void Main()
        {
            new Program().Solve();
        }
    }
}