Go: package main

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

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve()
}

func resolve() {
	results := []int{}
	for true {
		w, h := scanInt(sc), scanInt(sc)
		if w == 0 && h == 0 {
			break
		}
		grid := make([][]int, h)
		for i := 0; i < h; i++ {
			grid[i] = make([]int, w)
			for j := 0; j < w; j++ {
				grid[i][j] = scanInt(sc)
			}
		}
		num := 0
		for i := range loop0(h) {
			for j := range loop0(w) {
				start := pos{y: i, x: j}
				if grid[start.y][start.x] == 0 {
					continue
				}
				num++
				_dfs(grid, w, h, start)
			}
		}
		results = append(results, num)
	}
	for _, v := range results {
		fmt.Println(v)
	}
	return
}

func _dfs(grid [][]int, w, h int, start pos) {
	grid[start.y][start.x] = 0
	for _, df := range []pos{
		pos{1, 0}, pos{-1, 0},
		pos{0, -1}, pos{0, 1},
		pos{1, 1}, pos{-1, -1},
		pos{-1, 1}, pos{1, -1},
	} {
		np := addPos(start, df)
		if np.y < 0 || h <= np.y || np.x < 0 || w <= np.x {
			continue
		}
		if grid[np.y][np.x] == 0 {
			continue
		}
		_dfs(grid, w, h, np)
	}
}

type pos struct{ x, y int }

func addPos(p, d pos) pos {
	return pos{
		x: p.x + d.x,
		y: p.y + d.y,
	}
}

func loop0(n int) chan int {
	return loop(0, n-1, 1)
}

func loop1(n int) chan int {
	return loop(1, n, 1)
}

func loop(s, e, d int) chan int {
	ch := make(chan int)
	go func() {
		for i := s; i <= e; i += d {
			ch <- i
		}
		close(ch)
	}()
	return ch
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

C++: #include<stdio.h>
#include<stdlib.h>
#include<iostream>
#include<string.h>
#include<math.h>
#include<cstring>
using namespace std;

int w,h,c[50][50];
void island(int i,int j){
	int x,y;
	c[i][j]=0;
	for(x=-1;x<=1;x++){
		for(y=-1;y<=1;y++){
			if(0<=j+x&&j+x<w&&0<=i+y&&i+y<h&&c[i+y][j+x]==1){
				island(i+y,j+x);
			}
		}
	}

}
int main(){
	while(1){
		int sum=0,i,j,i1,j1;
		for(i=0;i<50;i++){
			for(j=0;j<50;j++){
				c[i][j]=0;
			}
		}
		cin>>w>>h;
		if(w==0&&h==0)break;
		for(i=0;i<h;i++){
			for(j=0;j<w;j++){
				cin>>c[i][j];
			}
		}
		for(i=0;i<h;i++){
			for(j=0;j<w;j++){
				if(c[i][j]==1){
					island(i,j);
					sum++;
				}
			}
		}
		cout<<sum<<endl;
	}
    return 0;
}

C++: #include <bits/stdc++.h>
 
#define loop(n, i) for(int i=0;i<n;i++)
#define all(v) v.begin(),v.end()

using namespace std;
using ll = long long;

int C[100][100] = {};
int vis[100][100] = {};

int dfs(int i, int j)
{
    int d[] = {1, 0, -1};
    if (!vis[i][j] && C[i][j]) {
        vis[i][j] = 1;
        loop (3, x) loop (3, y) dfs(i + d[x], j + d[y]);
    }
}

int main()
{
    while (1) {
        fill(C[0], C[99]+100, 0);
        fill(vis[0], vis[99]+100, 0);

        int w, h; cin >> w >> h;
        if (!w && !h) break;
        loop (h, i) loop (w, j) cin >> C[i+1][j+1];

        int ans = 0;
        loop (h, i) loop (w, j) {
            if (vis[i+1][j+1] || !C[i+1][j+1]) continue;
            ans++;
            dfs(i+1, j+1);
        }
        cout << ans << endl;
    }
    return 0;
}

C++: #include <iostream>
using namespace std;

int islands=0;
int w,h;
int field[50][50];
void bfs(int, int);

int main(){

  while(cin>>w>>h&&w!=0&&h!=0){

    for(int i=0;i<51;i++){
      for(int j=0;j<51;j++){
        field[i][j] = 0;
      }
    }

    for(int j=0;j<h;j++){
      for(int i=0;i<w;i++){
        cin >> field[i][j];
//        cout << field[i][j] << " ";
      }
  //    cout << endl;
    }
   // cout << endl;
    int ans=0; 

    for(int i=0;i<w;i++){
      for(int j=0;j<h;j++){
        if(field[i][j]==1){
          field[i][j]=0;
          bfs(i,j);
          ans++;
        }
      }
    }
    /*   if(w==5&&h==4){
         for(int i=0;i<w;i++){
         for(int j=0;j<h;j++){
         cout << field[i][j] << " ";
         }
         cout << endl;
         }
         }*/
    cout << ans << endl;
  }

  return 0;
}

void bfs(int x, int y){
  if(x-1>=0&&field[x-1][y]==1){
    field[x-1][y]=0;
    bfs(x-1,y);
  }
  if(x+1<w&&field[x+1][y]==1){
    field[x+1][y]=0;
    bfs(x+1,y);
  }
  if(y-1>=0&&field[x][y-1]==1){
    field[x][y-1]=0;
    bfs(x,y-1);
  }
  if(y+1<h&&field[x][y+1]==1){
    field[x][y+1]=0;
    bfs(x, y+1);
  }
  if(x-1>=0&&y-1>=0&&field[x-1][y-1]==1){
    field[x-1][y-1]=0;
    bfs(x-1,y-1);
  }
  if(x+1<w&&y-1>=0&&field[x+1][y-1]==1){
    field[x+1][y-1]=0;
    bfs(x+1,y-1);
  }
  if(x-1>=0&&y+1<h&&field[x-1][y+1]==1){
    field[x-1][y+1]=0;
    bfs(x-1,y+1);
  }
  if(x+1<w&&y+1<h&&field[x+1][y+1]==1){
    field[x+1][y+1]=0;
    bfs(x+1,y+1);
  }
  return;
}