Go: package main

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

func getScanner(fp *os.File) *bufio.Scanner {
	scanner := bufio.NewScanner(fp)
	scanner.Split(bufio.ScanWords)
	scanner.Buffer(make([]byte, 1000005), 1000005)
	return scanner
}

func getNextString(scanner *bufio.Scanner) string {
	scanner.Scan()
	return scanner.Text()
}

func getNextInt(scanner *bufio.Scanner) int {
	i, _ := strconv.Atoi(getNextString(scanner))
	return i
}

func getNextInt64(scanner *bufio.Scanner) int64 {
	i, _ := strconv.ParseInt(getNextString(scanner), 10, 64)
	return i
}

func getNextUint64(scanner *bufio.Scanner) uint64 {
	i, _ := strconv.ParseUint(getNextString(scanner), 10, 64)
	return i
}

func getNextFloat64(scanner *bufio.Scanner) float64 {
	i, _ := strconv.ParseFloat(getNextString(scanner), 64)
	return i
}

func main() {
	fp := os.Stdin
	wfp := os.Stdout
	cnt := 0

	if os.Getenv("MASPY") == "ますピ" {
		fp, _ = os.Open(os.Getenv("BEET_THE_HARMONY_OF_PERFECT"))
		cnt = 0
	}
	if os.Getenv("MASPYPY") == "ますピッピ" {
		wfp, _ = os.Create(os.Getenv("NGTKANA_IS_GENIUS10"))
	}

	scanner := getScanner(fp)
	writer := bufio.NewWriter(wfp)
	for solve(scanner, writer) {

	}
	for i := 0; i < cnt; i++ {
		fmt.Fprintln(writer, "-----------------------------------")
		solve(scanner, writer)
	}
	writer.Flush()
}

func solve(scanner *bufio.Scanner, writer *bufio.Writer) bool {
	sol := solver{}
	sol.w = getNextInt(scanner)
	sol.h = getNextInt(scanner)
	if sol.w == 0 && sol.h == 0 {
		return false
	}
	sol.land = makeInts(sol.h, sol.w)
	for y := 0; y < sol.h; y++ {
		for x := 0; x < sol.w; x++ {
			sol.land[y][x] = getNextInt(scanner)
		}
	}
	ans := 0
	for y := 0; y < sol.h; y++ {
		for x := 0; x < sol.w; x++ {
			if sol.land[y][x] == 0 {
				continue
			}
			ans++
			sol.dfs(y, x)
		}
	}
	fmt.Fprintln(writer, ans)
	return true
}

type solver struct {
	w, h int
	land [][]int
}

func (sol *solver) dfs(y, x int) {
	if y < 0 {
		return
	}
	if y >= sol.h {
		return
	}
	if x < 0 {
		return
	}
	if x >= sol.w {
		return
	}
	if sol.land[y][x] == 0 {
		return
	}
	sol.land[y][x] = 0
	dy := [8]int{-1, -1, -1, 0, 0, 1, 1, 1}
	dx := [8]int{-1, 0, 1, -1, 1, -1, 0, 1}
	for i := 0; i < 8; i++ {
		sol.dfs(y+dy[i], x+dx[i])
	}
}
func makeInts(h, w int) [][]int {
	index := make([][]int, h, h)
	data := make([]int, h*w, h*w)
	for i := 0; i < h; i++ {
		index[i] = data[i*w : (i+1)*w]
	}
	return index
}

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

using namespace std;
using vec = vector<int>;
using mat = vector<vec>;

void init(vec & parent)
{
	for (int i = 0; i < parent.size(); ++i)
	{
		parent[i] = i;
	}
}

int find(vec & parent, int x)
{
	if (parent[x] == x)return x;
	return parent[x] = find(parent, parent[x]);
}

void unite(vec & parent, int x, int y)
{
	x = find(parent, x);
	y = find(parent, y);
	if (x == y)return;
	parent[y] = x;
}

int change(int y, int x, int W)
{
	return y*W + x;
}


int main()
{
	while (true)
	{
		int w, h;
		cin >> w >> h;

		if (w == 0 && h == 0)return 0;

		mat c(h, vec(w));
		vec parent(h*w);

		init(parent);

		for (int y = 0; y < h; ++y)
		{
			for (int x = 0; x < w; ++x)
			{
				cin >> c[y][x];

				if (x != 0 && c[y][x] == c[y][x - 1])
				{
					unite(parent, change(y, x, w), change(y, x - 1, w));
				}
				if (y != 0 && c[y][x] == c[y - 1][x])
				{
					unite(parent, change(y, x, w), change(y - 1, x, w));
				}
				if (x != 0 && y != 0 && c[y][x] == c[y - 1][x - 1])
				{
					unite(parent, change(y, x, w), change(y - 1, x - 1, w));
				}
				if (x != w - 1 && y != 0 && c[y][x] == c[y - 1][x + 1])
				{
					unite(parent, change(y, x, w), change(y - 1, x + 1, w));
				}
			}
		}

		int ans = 0;
		for (int y = 0; y < h; ++y)
		{
			for (int x = 0; x < w; ++x)
			{
				int i = change(y, x, w);
				ans += parent[i] == i && c[y][x] == 1;
			}
		}
		cout << ans << endl;
	}
	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;
//入力
int H,W;
vector<vector<int>> field;

void dfs(int h,int w){
  field[h][w] = 0;
  // 八方向を探索
  for(int dh=-1;dh<=1;dh++){
    for(int dw=-1;dw<=1;dw++){
      int nh = h+dh,nw=w+dw;
      //場外アウトしたり、0だったりはスルー
      if(nh<0||nh>=H||nw<0||nw>=W) continue;
      if(field[nh][nw]==0) continue;
      dfs(nh,nw);//再帰的に探索
    }
  }
}

int main(){
  //入力受け取り
  while(cin >> W >> H){
    if(H==0||W==0) break;
    field.assign(H,vector<int>(W,0));
    for(int h=0;h<H;h++)for(int w=0;w<W;w++) cin >> field[h][w];
    int count = 0;
    for(int h=0;h<H;h++){
      for(int w=0;w<W;w++){
        if(field[h][w]==0) continue;//残島じゃなかったらスルー
        dfs(h,w);
        ++count;
      }
    }
    cout << count << endl;
  }
}

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

using namespace std;

	ifstream fin;
	ofstream fout;

	//http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160&lang=jp

	int gomi = 0;

	int a[52][52] = {};
	int check(int, int);

	int main(){

		fin.open("input.txt");
		fout.open("output.txt");

		//		int w = 0, h = 0;
		int width = 0, height = 0;
		int count = 0;


		while (1){
			for (int i = 0; i < 50; i++)
				for (int j = 0; j < 50; j++)
					a[i + 1][j + 1] = 0;

			cin >> width >> height;
			if (width == 0 && height == 0)break;

			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
					//初期化
					gomi = a[i + 1][j + 1] = 0;

					cin >> a[i + 1][j + 1];
				}
			}

			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
				}
			}
			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
					if (a[i + 1][j + 1] == 1){
						check(i + 1, j + 1);
						a[i + 1][j + 1] = 1;
						count++;
					//	cout << i + 1 << "  " << j + 1 << endl;
					}
				}
			}
//			cout << count << endl;
			fout << count << endl;

			//初期化
			count = 0;
			for (int i = 0; i < height; i++){
				for (int j = 0; j < width; j++){
					a[i + 1][j + 1] = 0;
				}
			}
		}
	}

	int check(int y, int x){
		if (a[y + 1][x] == 1){
			a[y + 1][x] = 0;
			check(y + 1, x);
		}
		//-----------------------------
		if (a[y][x + 1] == 1){
			a[y][x + 1] = 0;
			check(y, x + 1);
		}
		//-----------------------------
		if (a[y - 1][x] == 1){
			a[y - 1][x] = 0;
			check(y - 1, x);
		}
		//-----------------------------
		if (a[y][x - 1] == 1){
			a[y][x - 1] = 0;
			check(y, x - 1);
		}
		//-----------------------------
		if (a[y + 1][x + 1] == 1){
			a[y + 1][x + 1] = 0;
			check(y + 1, x + 1);
		}
		//-----------------------------
		if (a[y + 1][x - 1] == 1){
			a[y + 1][x - 1] = 0;
			check(y + 1, x - 1);
		}
		//-----------------------------
		if (a[y - 1][x + 1] == 1){
			a[y - 1][x + 1] = 0;
			check(y - 1, x + 1);
		}
		//-----------------------------
		if (a[y - 1][x - 1] == 1){
			a[y - 1][x - 1] = 0;
			check(y - 1, x - 1);
		}
		//-----------------------------
		return 0;
	}

C++: #include <bits/stdc++.h>
using namespace std;

int state[100][100];
bool reached[100][100];
int w,h;

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

void dfs(int x, int y) {

	if(x==0 || w<x || y==0 || h<y || state[x][y] == 0)
		return;
	if(reached[x][y] == true)
		return;

	reached[x][y]=true;

	for(int i=0; i<8; i++) {
		dfs(x+dx[i],y+dy[i]);
	}
}

int main() {

	while(1){
		cin >> w >> h;
		if(w==0 && h==0) {
			return 0;
		}
		memset(state, 0, sizeof(state));
		memset(reached, false, sizeof(reached));
		for(int i=1; i<=h; i++) {
			for(int j=1; j<=w; j++) {
				cin >> state[i][j];
			}
		}
		int count=0;
		for(int i=1; i<=w; i++) {
			for(int j=1; j<=h; j++) {
				if(reached[i][j]==true || state[i][j] == 0)
					continue;
				else{
					dfs(i,j);
					count++;
				}
			}
		}
		cout << count << endl;
	}
	return 0;
}