using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace ProgrammingContest
{
    class Writer : IDisposable
    {
        private readonly System.IO.TextWriter writer;
        private StringBuilder sb;
        private readonly bool isReactive;
        public Writer(string path)
            : this(new System.IO.StreamWriter(path))
        {
        }
        public Writer(bool isReactive)
            : this(null, isReactive)
        {
        }
        public Writer(System.IO.TextWriter writer = null,
                        bool isReactive = false)
        {
            this.writer = (writer ?? Console.Out);
            this.isReactive = isReactive;
            if (!this.isReactive)
            {
                this.sb = new StringBuilder();
            }
        }
        public void Dispose()
        {
            if (!this.isReactive)
            {
                this.writer.Write(sb.ToString());
            }
            if (!this.writer.Equals(Console.Out))
            {
                this.writer.Dispose();
            }
        }
        public void Write(object val)
        {
            if (this.isReactive)
            {
                this.writer.Write(val.ToString());
                this.writer.Flush();
            }
            else
            {
                this.sb.Append(val.ToString());
            }
        }
        public void Write(string format, params object[] vals)
        {
            if (this.isReactive)
            {
                this.writer.Write(format, vals);
                this.writer.Flush();
            }
            else
            {
                this.sb.AppendFormat(format, vals);
            }
        }
        public void WriteLine(object val = null)
        {
            this.Write((val ?? string.Empty).ToString() + System.Environment.NewLine);
        }
        public void WriteLine(int val)
        {
            this.WriteLine(val.ToString());
        }
        public void WriteLine(long val)
        {
            this.WriteLine(val.ToString());
        }
        public void WriteLine(string val)
        {
            this.WriteLine((object)val);
        }
        public void WriteLine(string format, params object[] vals)
        {
            this.Write(format + System.Environment.NewLine, vals);
        }
    }

    class Scanner : IDisposable
    {
        private readonly Queue<string> buffer;
        private readonly char[] sep;
        private readonly System.IO.TextReader reader;
        public Scanner(string path, char[] sep = null)
            : this(new System.IO.StreamReader(path), sep)
        {
        }
        public Scanner(System.IO.TextReader reader = null,
                        char[] sep = null)
        {
            this.buffer = new Queue<string>();
            this.sep = (sep ?? new char[] { ' ' });
            this.reader = (reader ?? Console.In);
        }
        private void CheckBuffer()
        {
            if (this.buffer.Count == 0 && this.reader.Peek() != -1)
            {
                string str = string.Empty;
                for (; string.IsNullOrEmpty(str);
                    str = this.reader.ReadLine()) ;

                str.Split(this.sep).ToList()
                   .ForEach(el => this.buffer.Enqueue(el));
            }
        }

        public void Dispose()
        {
            if (!this.reader.Equals(Console.In))
            {
                this.reader.Dispose();
            }
        }

        public string Next
        {
            get
            {
                this.CheckBuffer();
                return this.buffer.Dequeue();
            }
        }
        public string[] GetStringArray(int N)
        {
            return Enumerable.Range(0, N)
                             .Select(e => this.Next)
                             .ToArray();
        }

        public int NextInt
        {
            get
            {
                return int.Parse(this.Next);
            }
        }
        public int[] GetIntArray(int N)
        {
            return Enumerable.Range(0, N)
                             .Select(e => this.NextInt)
                             .ToArray();
        }

        public double NextDouble
        {
            get
            {
                return double.Parse(this.Next);
            }
        }
        public double[] GetdoubleArray(int N)
        {
            return Enumerable.Range(0, N)
                             .Select(e => this.NextDouble)
                             .ToArray();
        }

        public long NextLong
        {
            get
            {
                return long.Parse(this.Next);
            }
        }
        public long[] GetLongArray(int N)
        {
            return Enumerable.Range(0, N)
                             .Select(e => this.NextLong)
                             .ToArray();
        }

        public bool IsEnd
        {
            get
            {
                this.CheckBuffer();
                return this.buffer.Count == 0;
            }
        }
    }

    class MainClass : IDisposable
    {
        Scanner sc;
        Writer wr;
        const string backPath = "..";
        private readonly char dirSep = System.IO.Path.DirectorySeparatorChar;
        private readonly string inFilePath = string.Empty;
        private readonly string outFilePath = string.Empty;
        public MainClass()
        {
            this.inFilePath = MainClass.backPath
                            + this.dirSep
                            + MainClass.backPath
                            + this.dirSep
                            + "in.txt";
            this.outFilePath = MainClass.backPath
                             + this.dirSep
                             + MainClass.backPath
                             + this.dirSep
                             + "out.txt";

            this.wr = new Writer(this.IsReactive);
            //this.wr = new Writer(this.outFilePath);
#if DEBUG
            if (!this.IsReactive)
            {
                this.sc = new Scanner(this.inFilePath);
            }
            else
            {
                this.sc = new Scanner();
            }
#else
            this.sc = new Scanner();
#endif
        }
        static void Main(string[] args)
        {
            using (var mainClass = new MainClass())
            {
                mainClass.Solve();
            }
        }

        public void Dispose()
        {
            if (this.sc != null)
            {
                this.sc.Dispose();
                this.sc = null;
            }
            if (this.wr != null)
            {
                this.wr.Dispose();
                this.wr = null;
            }
#if DEBUG
            Console.WriteLine("続行するには何かキーを押してください...");
            Console.ReadKey();
#endif
        }

        void MakeTestCase()
        {
            var rand = new Random();
            if (this.wr != null)
            {
                this.wr.Dispose();
            }
            this.wr = new Writer(inFilePath);


        }

        void Solve()
        {
            int H = sc.NextInt;
            int W = sc.NextInt;
            bool[,] A = new bool[H, W];
            for (int i = 0; i < H; i++)
            {
                for (int j = 0; j < W; j++)
                {
                    A[i, j] = sc.NextInt == 1;
                }
            }
            UnionFind uf = new UnionFind(H * W);
            int blank = 0;
            int[] nh = new int[] { -1, 0, 0, 1 };
            int[] nw = new int[] { 0, -1, 1, 0 };
            Func<int, int, bool> In = (ii, jj) =>
            {
                return 0 <= ii && ii < H && 0 <= jj && jj < W;
            };
            for (int i = 0; i < H; i++)
            {
                for (int j = 0; j < W; j++)
                {
                    if (A[i, j])
                    {
                        for (int k = 0; k < 4; k++)
                        {
                            int ni = i + nh[k];
                            int nj = j + nw[k];
                            if (In(ni, nj) && A[ni, nj])
                            {
                                uf.Unite(i * W + j, ni * W + nj);
                            }
                        }
                    }
                    else
                    {
                        blank++;
                    }
                }
            }
            wr.WriteLine(uf.Count() - blank);
        }
        class UnionFind
        {
            private int[] uni;
            int count_;
            public UnionFind(int n)
            {
                this.uni = new int[n];
                for (int i = 0; i < n; i++)
                {
                    this.uni[i] = -1;
                }
                this.count_ = n;
            }
            public int Count()
            {
                return this.count_;
            }
            public int Count(int n)
            {
                return -this.uni[this.Find(n)];
            }
            public int Find(int n)
            {
                return (this.uni[n] < 0 ? n : this.uni[n] = this.Find(this.uni[n]));
            }
            public bool Unite(int a, int b)
            {
                a = this.Find(a);
                b = this.Find(b);
                if (a == b)
                {
                    return false;
                }
                if (this.uni[a] > this.uni[b])
                {
                    int t = a;
                    a = b;
                    b = t;
                }
                this.uni[a] += this.uni[b];
                this.uni[b] = a;
                this.count_--;
                return true;
            }
            public bool Same(int a, int b)
            {
                return this.Find(a) == this.Find(b);
            }
        }
        private bool IsReactive { get; } = false; // TODO: reactive check !!
    }
}