Go: package main

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

var sc = bufio.NewScanner(os.Stdin)
var route [][]int

func scanInt() int {
	num, _ := strconv.Atoi(scanString())
	return num
}

func scanString() string {
	sc.Scan()
	return sc.Text()
}

func init() {
	sc.Split(bufio.ScanWords)
}

func dfs(h, w int) {
	if route[h][w] == 0 {
		return
	}

	route[h][w] = 0
	for _, x := range []int{-1, 0, 1} {
		for _, y := range []int{-1, 0, 1} {
			if route[h+x][w+y] == 0 {
				continue
			}
			dfs(h+x, w+y)
		}
	}
}

func main() {
	writer := bufio.NewWriter(os.Stdout)
	for {
		w, h := scanInt(), scanInt()
		if w == 0 && h == 0 {
			break
		}

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

		total := 0
		for i := 1; i <= h; i++ {
			for j := 1; j <= w; j++ {
				if route[i][j] == 1 {
					total++
					dfs(i, j)
				}
			}
		}
		fmt.Fprintln(writer, total)
	}
	writer.Flush()
}

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

#define MAX 51

bool field[MAX][MAX];
int cnt;
int H, W;

void dfs(int x, int y){
  field[x][y] = 0;
  
  for(int dx = -1 ; dx <= 1 ; dx++){
    for(int dy = -1 ; dy <= 1 ; dy++){
      int nx = x + dx;
      int ny = y + dy;
      if(0 <= nx && nx < H && 0 <= ny && ny < W && field[nx][ny] == 1) dfs(nx, ny);
    }
  }
}

int main(){
  while(cin >> W >> H){
    cnt = 0;
    if(W == 0 && H == 0) break;
    for(int i = 0 ; i < H ; i++){
      for(int j = 0 ; j < W ; j++){
	cin >> field[i][j];
      }
    }

    for(int i = 0 ; i < H ; i++){
      for(int j = 0 ; j < W ; j++){
	if(field[i][j] == 1){
	  dfs(i, j);
	  cnt++;
	}
      }
    }
    cout << cnt << endl;
  }
  return 0;
}

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

using namespace std;

#define rep(i, n) for (int i = 0; i < n; i++)
#define vec vector

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

int dp[55][55];
int c[55][55];

int check(int x, int y)
{
	if (dp[x][y]) return 0;
	if (c[x][y] == 0) return 0;
	dp[x][y] = 1;
	
	rep(i, 8) {
		int xx = x + dx[i];
		int yy = y + dy[i];
		int take = check(xx, yy);
	}
	return 1;
}

int main(void)
{
	while(1) {
		int w, h;
		cin >> w >> h;
		if (w == 0) break;
		rep(i, 55) rep(j, 55) c[i + 1][j + 1] = 0;
		rep(i, h) rep (j, w) cin >> c[i + 1][j + 1];
		rep(i, 55) rep(j, 55) dp[i][j] = 0;
		rep(i, 55) {
			dp[0][i] = 1;
			dp[i][0] = 1;
			dp[h + 1][i] = 1;
			dp[i][w + 1] = 1;
		}

		int ans = 0;
		rep(i, h) rep(j, w) if (c[i + 1][j + 1]) ans += check(i + 1, j + 1);
		cout << ans << endl;
	}
	return 0;
}

C++: #include<iostream>

using namespace std;

int map[50][50];
int h,w;
int dx[]={-1,0,1},dy[]={-1,0,1};
void solve(void);
void loop(int ,int );
void draw(void);
int main(){
	while(cin>>h>>w,h){
		for(int i=0;i<w;i++){
			for(int j=0;j<h;j++){
				cin>>map[i][j];
			}
		}
		solve();
		for(int i=0;i<w;i++){
			for(int j=0;j<h;j++){
				map[i][j]=0;
			}
		}
	}
	return 0;
}
void solve(void){
	int cnt=0;
	for(int i=0;i<w;i++){
		for(int j=0;j<h;j++){
			if(map[i][j]==1){
				loop(i,j);	
				cnt++;	
			}
		}
	}
	cout<<cnt<<endl;
}
void loop(int x,int y){
	map[x][y]=0;
	for(int i=0;i<3;i++){
		for(int j=0;j<3;j++){
			
			if(map[x+dx[i]][y+dy[j]]==1){
				loop(x+dx[i],y+dy[j]);
			}
		}
	}
	return ;
}

C++: #include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < (int)(n); ++i)
#define REP2(i, m, n) for (int i = (m); i < (int)(n); ++i)
#define REPR(i, n) for (int i = (n)-1; i >= 0; --i)
#define REPR2(i, m, n) for (int i = (n)-1; i >= (m); --i)
#define REPx(x, a) for(auto x : a)
#define ALL(a) a.begin(), a.end()
#define SORT(a) sort(ALL(a))
#define SORTR(a) sort(ALL(a), greater<int>())
#define REVERSE(a) reverse(ALL(a))
#define bit_search(bit, n) REP(bit, 1<<(n))
#define bit_check(bit, i) ((bit>>(i)) & 1)
#define setpre(n) fixed << setprecision((n))
#define UNIQUE(a) do {SORT(a); (a).erase(unique(ALL(a)), (a).end());} while(0)
#define MAX(a) *max_element(ALL(a))
#define MIN(a) *min_element(ALL(a))
#define bisect_left(a, x) lower_bound(ALL(a), (x)) - a.begin()
#define bisect_right(a, x) upper_bound(ALL(a), (x)) - a.begin()
#define INPUT(a) REP(i, a.size()) cin >> a[i];
#define INPUTP(a) REP(i, a.size()) cin >> a[i].first >> a[i].second;
#define OUTPUT_PERMUTATION(n) do{VI v(n); iota(ALL(v), 1); do{REPx(x, v) cout << x << " "; ENDL} while(next_permutation(ALL(v)));} while(0);
#define MAKE_PERMUTATION(n) do{VVI a(fact(n), VI(n)); int idx = 0; VI v(n); iota(ALL(v), 1); do{REP(i, n) a[idx][i] = v[i]; idx++; PER = a;} while(next_permutation(ALL(v)));} while(0); // int fact(), VVI PERを宣言しておく
#define ENDL cout << endl;
using namespace std;

int w, h;
vector<int> px = {0, 1, 0, -1, 1, 1, -1, -1}, py = {1, 0, -1, 0, 1, -1, 1, -1};

void dfs(vector<vector<char>> M, vector<vector<bool>>& reached, int x, int y)
{
  reached[y][x] = true;
  REP(i, 8)
  {
    int xx = x + px[i], yy = y + py[i];
    if (0 <= xx && xx < w && 0 <= yy && yy < h && M[yy][xx] == '1' && !reached[yy][xx]) dfs(M, reached, xx, yy);
  }
}

int main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  while(true)
  {
    int ans = 0;
    cin >> w >> h;
    if(w == 0 && h == 0) return 0;
    vector<vector<char>> M(h, vector<char>(w));
    REP(y, h) REP(x, w) cin >> M[y][x];
    vector<vector<bool>> reached(h, vector<bool>(w, false));
    REP(y, h) REP(x, w)
    {
      if (reached[y][x] || M[y][x] == '0') continue;
      ans++;
      dfs(M, reached, x, y);
    }
    cout << ans << endl;
  }

  return 0;
}