using System;
using System.Collections.Generic;
using System.IO;

namespace No697
{
    public class Program
    {
        readonly int[] dx = {0, 1, 0, -1};
        readonly int[] dy = {1, 0, -1, 0};
        readonly int dl = 4;
        bool IsInside(int x, int y) => 0 <= x && x < W && 0 <= y && y < H;

        int H;
        int W;
        bool[,] A;

        void Solve(StreamReader sr, StreamWriter sw)
        {
            //---------------------------------
            var input = sr.ReadLine().Split(' ');

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

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

            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);
                }
            }

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

        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);
                }
            }
        }

        static void Main()
        {
            var ss = new StreamReader(Console.OpenStandardInput());
            var sw = new StreamWriter(Console.OpenStandardOutput()) {AutoFlush = false};
            new Program().Solve(ss, sw);
            sw.Flush();
        }

        static readonly Func<string, string> String = s => s;
    }
}