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;

bool f[51][51];
int w, h;
int dx[8] = { 0, 0, -1,  1, -1,  1, -1,  1};
int dy[8] = {-1, 1,  0,  0, -1, -1,  1,  1};

void dfs(int x, int y) {
	if(!f[y][x]) return;
	f[y][x] = 0;
	for (int i = 0; i < 8; i++) {
		if (x + dx[i] < w && y + dy[i] < h
			 && x + dx[i] >= 0 && y + y + dy[i] >= 0)
			dfs(x + dx[i], y + dy[i]);
	}
}

int main()
{	
	int n;
	
	while (cin >> w >> h, w) {
		n = 0;
		
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				cin >> f[i][j];
			}
		}
		
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (f[i][j]) {
					n++;
					dfs(j, i);
				}
			}
		}
		
		cout << n << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for (ll i = 0; i < n; ++i)
#define sz(x) int(x.size())
#define ALL(c) (c).begin(), (c).end()
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v, x) (std::find(v.begin(), v.end(), x) != v.end())
#define FORV(i, v) for (auto i = v.begin(); i != v.end(); i++)
using namespace std;

using ll = long long;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
const int INF = 1001001001;
const long long INFLL = LLONG_MAX / 3;
const double eps = (1e-9);

int dh[] = {-1, -1, -1, 0, 0, 1, 1, 1};
int dw[] = {-1, 0, 1, -1, 1, -1, 0, 1};

void dfs(const vector<vector<int>>& c, vector<vector<bool>>& visited, int h, int w) {
  visited[h][w] = true;
  rep(i, 8) {
    int nh = h + dh[i];
    int nw = w + dw[i];
    if (nh < 0 || nh >= c.size() || nw < 0 || nw >= c[0].size()) continue;
    if (visited[nh][nw]) continue;
    if (c[nh][nw] == 0) continue;
    dfs(c, visited, nh, nw);
  }
}

bool solve() {
  int w, h; cin >> w >> h;
  if (w == 0 && h == 0) return false;
  vector<vector<int>> c(h, vector<int>(w));
  rep(i, h) rep(j, w) cin >> c[i][j];
  vector<vector<bool>> visited(h, vector<bool>(w, false));

  int ans = 0;
  rep(i, h) rep(j, w) {
    if (visited[i][j]) continue;
    if (c[i][j] == 0) continue;
    dfs(c, visited, i, j);
    ans++;
  }
  cout << ans << endl;
  return true;
}

int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);

  while (solve()) {}

  return 0;
}

C++: #include<iostream>
#include<string>
using namespace std;
int dp[50][50];
int main(){
	int w,h;
	while(true){
	cin>>w>>h;
	if(w==0&&h==0)
		break;
	for(int i=0;i<h;i++)
		for(int j=0;j<w;j++)
			cin>>dp[i][j];
	int count=0;
	while(true){
		bool t=true;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(dp[i][j]!=0)
					t=false;
			}
		}
		if(t==true)
			break;
		int x=0,y=0;
		while(true){
			x=0;
			while(true){
				if(dp[y][x]==1){
					t=true;
					break;
				}
				x++;
				if(x==w)
					break;
			}
			if(t==true)
				break;
			y++;
		}
		for(int f=max(0,y-1);f<=min(h-1,y+1);f++){
			for(int g=max(0,x-1);g<=min(w-1,x+1);g++){
				if(dp[f][g]==1)
				    dp[f][g]=2;
			}
		}
		dp[y][x]=0;
		while(true){
			t=true;
			for(int i=0;i<h;i++){
				for(int j=0;j<w;j++){
					if(dp[i][j]==2){
						for(int f=max(0,i-1);f<=min(h-1,i+1);f++){
			                for(int g=max(0,j-1);g<=min(w-1,j+1);g++){
								if(dp[f][g]==1)
				                    dp[f][g]=2;
			                }
						}
						dp[i][j]=0;
						t=false;
					}
				}
			}
			if(t==true)
				break;
		}
		count++;
	}
	cout<<count<<endl;
	}
	return 0;
}

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

int MAP(vector<vector<int>> &m, int i, int j){
	int w = m[0].size();
	int h = m.size();

	if(!(0 <= i && i < h && 0 <= j && j < w)){
		return 0;
	}

	if(m[i][j] == 0){
		return 0;
	}
	else if(m[i][j] = 1){
		m[i][j] = 0;
		MAP(m, i - 1, j - 1);
		MAP(m, i, j - 1);
		MAP(m, i + 1, j - 1);
		MAP(m, i - 1, j);
		MAP(m, i + 1, j);
		MAP(m, i - 1, j + 1);
		MAP(m, i, j + 1);
		MAP(m, i + 1, j + 1);
	}
	return 1;
}

int main(){
	int w, h;

	while(true){
		int count = 0;
		cin >> w >> h;

		if(w == 0 && h == 0){
			break;
		}

		vector<vector<int> > map(h, vector<int>(w, 0));

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

		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				count += MAP(map, i , j);
			}
		}

		cout << count << endl;
	}
}