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<bits/stdc++.h>
using namespace std;

const int dx[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
const int dy[8] = {1, 1, 1, 0, 0, -1, -1, -1};

int H, W;
int sima[55][55];

bool seen[55][55];
void dfs(int h, int w){
  seen[h][w] = true;
  for(int dir=0; dir<8; dir++){
    int nh = h + dy[dir];
    int nw = w + dx[dir];
    if(nh>=H || nh<0 || nw>=W || nw<0){
      continue;
    }
    if(sima[nh][nw] == 0){
      continue;
    }
    if(seen[nh][nw]){
      continue;
    }
    dfs(nh, nw);
  }
}

int main(){
  while(1){
    cin >> W >> H;
    if(H == 0 && W == 0){
      break;
    }
    for(int h=0; h<H; h++){
      for(int w=0; w<W; w++){
        cin >> sima[h][w];
      }
    }
    memset(seen, 0, sizeof(seen));
    int count=0;
    for(int i=0; i<H; i++){
      for(int j=0; j<W; j++){
        if(seen[i][j]){
          continue;
        }
        if(sima[i][j] == 0){
          continue;
        }
        dfs(i, j);
        count++;
      }
    }
    cout << count << endl;
  }
  return 0;
}

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

std::vector<int> dx{1, 1, 0, -1, -1, -1, 0, 1};
std::vector<int> dy{0, 1, 1, 1, 0, -1, -1, -1};

void dfs(std::vector<std::vector<bool>> &seen, std::vector<std::vector<int>> &map, int x, int y){
//    std::cout << x << ", " << y << std::endl;
    seen.at(y).at(x) = true;
    for(int i = 0; i < 8; ++i){
        int nextX = x + dx.at(i), nextY = y + dy.at(i);
        if(!seen.at(nextY).at(nextX) && 1 == map.at(nextY).at(nextX)){
            dfs(seen, map, nextX, nextY);
        }
    }
}

int main(){
    int w, h;
    while(std::cin >> w >> h){
        if(0 == w && 0 == h){
            break;
        }

        std::vector<std::vector<int>> map(h + 2, std::vector<int>(w + 2, 0));
        for(int i = 1; i <= h; ++i){
            for(int j = 1; j <= w; ++j){
                std::cin >> map.at(i).at(j); 
            }
        }

        std::vector<std::vector<bool>> seen(h + 2, std::vector<bool>(w + 2, false));
        int count = 0;
        for(int i = 1; i <= h; ++i){
            for(int j = 1; j <= w; ++j){
                if(!seen.at(i).at(j) && 1 == map.at(i).at(j)){
                    dfs(seen, map, j, i);
                    ++count;
                } 
            }
        }
    
        std::cout << count << std::endl;
    }

    return 0;
}

C++: 
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <vector>
#include <string>
#include <queue>
#include <algorithm>
#include <math.h>
#include <utility>
#include <set>
#include <map>
#define INF 100000
#define rep(i,n) for(int i =0;i<n;i++)
using namespace std;
typedef long long int ll;

#define MAX 5000

int G[51][51];
int h,w;


void dfs(int x, int y){
    if(x<0||x>w||y<0||y>h) return;
    for (int i=-1; i<=1; i++) {
        for (int j=-1; j<=1; j++) {
            if (G[x+i][y+j]==1) {
                G[x+i][y+j]=0;
                dfs(x+i,y+j);
            }
        }
    }
}


int main(){
    for(;;){
        cin >> w >> h;
        if(w==0 and h == 0) break;
        int ans=0;
        for (int i=0; i<h; i++) {
            for (int j=0; j<w; j++) {
                G[i][j]=0;
            }
        }
        for (int i = 0; i<h;i++) {
            for (int j=0; j < w; j++) {
                cin >> G[i][j];
            }
        }
        for (int i=0; i<h; i++) {
            for (int j=0; j<w; j++) {
                if (G[i][j]==1) {
                    G[i][j]=0;
                    ans++;
                    dfs(i,j);
                }
            }
        }
        cout << ans <<endl;
    }
}