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

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(StreamScanner ss, StreamWriter sw)
        {
            //---------------------------------
            H = ss.Next(int.Parse);
            W = ss.Next(int.Parse);
            A = ss.Next(s => s == "1", W, H);

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

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

        void Dfs(int x, int y)
        {
            A[y][x] = false;

            for (var i = 0; i < dl; i++)
            {
                var nx = x + dx[i];
                var ny = y + dy[i];
                if (IsInside(nx, ny) && A[ny][nx]) Dfs(nx, ny);
            }
        }

        static void Main()
        {
            var ss = new StreamScanner(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;
    }

    public class StreamScanner
    {
        static readonly char[] Sep = {' '};
        readonly Queue<string> buffer = new Queue<string>();
        readonly TextReader textReader;

        public StreamScanner(TextReader textReader)
        {
            this.textReader = textReader;
        }

        public T Next<T>(Func<string, T> parser)
        {
            if (buffer.Count != 0) return parser(buffer.Dequeue());
            var nextStrings = textReader.ReadLine().Split(Sep, StringSplitOptions.RemoveEmptyEntries);
            foreach (var nextString in nextStrings) buffer.Enqueue(nextString);
            return Next(parser);
        }

        public T[] Next<T>(Func<string, T> parser, int x)
        {
            var ret = new T[x];
            for (var i = 0; i < x; ++i) ret[i] = Next(parser);
            return ret;
        }

        public T[][] Next<T>(Func<string, T> parser, int x, int y)
        {
            var ret = new T[y][];
            for (var i = 0; i < y; ++i) ret[i] = Next(parser, x);
            return ret;
        }
    }
}