Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

var (
	readString func() string
	readBytes  func() []byte
	stdout     *bufio.Writer
)

func init() {
	readString, readBytes = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) (func() string, func() []byte) {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), math.MaxInt32)
	r.Split(bufio.ScanWords)

	f1 := func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
	f2 := func() []byte {
		return []byte(f1())
	}
	return f1, f2
}

func readInt() int {
	return int(readInt64())
}

func readInt64() int64 {
	i, err := strconv.ParseInt(readString(), 10, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(readString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

func printf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(stdout, f, args...)
}

func println(args ...interface{}) (int, error) {
	return fmt.Fprintln(stdout, args...)
}

func eprintln(args ...interface{}) (int, error) {
	return fmt.Fprintln(os.Stderr, args...)
}

func eprintf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(os.Stderr, f, args...)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func min64(a, b int64) int64 {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func max64(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func abs64(a int64) int64 {
	if a < 0 {
		return -a
	}
	return a
}

func gcd(a, b int) int {
	if b == 0 {
		return a
	}
	return gcd(b, a%b)
}

func gcd64(a, b int64) int64 {
	if b == 0 {
		return a
	}
	return gcd64(b, a%b)
}

// readString() string
// readInt() int
// readInt64() int64
// readFloat64() float64

// -----------------------------------------------------------------------------

func main() {
	defer stdout.Flush()

	for {
		ans, ok := solve()
		if !ok {
			break
		}
		println(ans)
	}

}

func solve() (int, bool) {
	w := readInt()
	h := readInt()
	if w == 0 && h == 0 {
		return 0, false
	}

	c := make([][]int, h+2)
	c[0] = make([]int, w+2)
	c[h+1] = make([]int, w+2)
	for i := 1; i-1 < h; i++ {
		c[i] = make([]int, w+2)
		for j := 1; j-1 < w; j++ {
			c[i][j] = readInt()
		}
	}

	var ans int
	for i := 1; i-1 < h; i++ {
		for j := 1; j-1 < w; j++ {
			if 0 < c[i][j] {
				ans++
				dfs(c, i, j)
			}
		}
	}
	return ans, true
}

func dfs(c [][]int, y, x int) {
	c[y][x] = 0
	dx := []int{-1, 0, 1, -1, 1, -1, 0, 1}
	dy := []int{-1, -1, -1, 0, 0, 1, 1, 1}
	for i := range dx {
		nx := x + dx[i]
		ny := y + dy[i]
		if 0 < c[ny][nx] {
			dfs(c, ny, nx)
		}
	}
}

// -----------------------------------------------------------------------------

C++: #include <iostream>
#include <queue>
#include <utility>

using namespace std;

using Point = pair<int,int>;

int map[50][50];

void BFS(const Point &p0){
  queue<Point> q;
  q.push(p0);
  while(!q.empty()){
    auto p = q.front();q.pop();
    int y = p.first , x = p.second;
    map[y][x] = 0;

    for(int i=-1;i<=1;++i){
      for(int j=-1;j<=1;++j){
        if(map[i+y][j+x]){
          q.push(Point(i+y,j+x));
        }
      }
    }
  }

}

int main(){
  int w,h;
  while(cin >> w >> h&&w>0&&h>0){
    for(int i=1;i<h+1;++i){
      for(int j=1;j<w+1;++j){
        cin >> map[i][j];
      }
    }

    int num = 0;
    for(int i=1;i<h+1;++i){
      for(int j=1;j<w+1;++j){
        if(map[i][j]){
          BFS(Point(i,j));
          num++;
        }
      }
    }
    cout << num << endl;
  }

  return 0;
}

C++: #include<iostream>
#include<algorithm>

using namespace std;

int field[52][52];

void DFS(int x, int y){
    if(field[x][y]==1){
        field[x][y]=-1;
        DFS(x-1,y-1);
        DFS(x,y-1);
        DFS(x+1,y-1);
        DFS(x-1,y);
        DFS(x+1,y);
        DFS(x-1,y+1);
        DFS(x,y+1);
        DFS(x+1,y+1);
    }
}


int main(){
    int w,h;
    while(cin>>w>>h){
        if(w==0&&h==0)break;
        for(int i=0; i<50; i++){
            for(int j=0; j<50; j++){
                field[i][j]=0;
            }
        }
        
        for(int i=1; i<=h; i++){
            for(int j=1; j<=w; j++){
                cin>>field[i][j];
            }
        }
        int sum=0;
        for(int i=1; i<=h; i++){
            for(int j=1; j<=w; j++){
                if(field[i][j]==1){
                    sum++;
                    DFS(i,j);
                }
            }
        }
        cout<<sum<<endl;
    }
}

C++: ///
// File:  1160.cpp
// Author: ymiyamoto
//
// Created on Sun Nov 12 16:15:22 2017
//

#include <array>
#include <cstdint>
#include <iostream>

using namespace std;

void dfs(int32_t h, int32_t w, array<array<uint32_t, 50>, 50> &arr, int32_t i, int32_t j)
{
  arr[i][j] = 0;

  for (int32_t l = -1; l <= 1; l++) {
    for (int32_t k = -1; k <= 1; k++) {
      if (0 <= i + l && i + l < h && 0 <= j + k && j + k < w) {
        if (arr[i + l][k + j] == 1) {
          dfs(h, w, arr, i + l, k + j);
        }
      }
    }
  }
}

int32_t main()
{
  while (true) {
    uint32_t w, h;
    cin >> w >> h;
    if (w == 0) break;

    array<array<uint32_t, 50>, 50> arr;
    for (uint32_t i = 0; i < h; i++) {
      for (uint32_t j = 0; j < w; j++) {
        cin >> arr[i][j];
      }
    }

    uint32_t count = 0;
    for (uint32_t i = 0; i < h; i++) {
      for (uint32_t j = 0; j < w; j++) {
        if (arr[i][j] == 1) {
          count++;
          dfs(h, w, arr, i, j);
        }
      }
    }
    cout << count << endl;
  }

  return 0;
}