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;
            bool IsInside(int x, int y) => 0 <= x && x < W && 0 <= y && y < H;

            void Bfs(int x, int y)
            {
                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 i = 0; i < dl; i++)
                    {
                        var nx = cx + dx[i];
                        var ny = cy + dy[i];
                        if (IsInside(nx, ny) && A[ny, nx]) Bfs(nx, ny);
                    }
                }
            }

            var ans = 0;
            for (var i = 0; i < H; i++)
            for (var j = 0; j < W; j++)
            {
                if (A[i, j])
                {
                    ans++;
                    Bfs(j, i);
                }
            }

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

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