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<iostream>
using namespace std;
const int MAXW = 51;
const int MAXH = 51;
int map[MAXW][MAXH];
int w,h;
int dx[] = {-1,0,1,-1,1,-1,0,1};
int dy[] = {1,1,1,0,0,-1,-1,-1};
int dfs(int x,int y){
  if(map[x][y] == 0)return 0;
  map[x][y] = 0;
  for(int i = 0;i < 9;i++){
    int nx = x+dx[i];
    int ny = y+dy[i];
    if(nx >= 0 && nx < w & ny >= 0 && ny < h)
      dfs(nx,ny);
  }
  return 1;
}

int main(){
  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 >> map[j][i];
      }
    }
    int count = 0;
    for(int i = 0;i < h;i++){
      for(int j = 0;j < w;j++){
        count += dfs(j,i);
      }
    }
    cout << count << endl;
  }
}

C++: #include<iostream>

using namespace std;

const int MaxI = 51;
int C[MaxI][MaxI];
int Dh[] = {-1,-1,-1,0,0,1,1,1};
int Dw[] = {-1,0,1,-1,1,-1,0,1};
int H, W;

void dfs(int i, int j);

int main() {

  while(cin>>W>>H && !(W==0 && H==0)) {
    for(int i=0; i<H; i++) {
      for(int j=0; j<W; j++) {
	cin>>C[i][j];
      }
    }

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

void dfs(int i, int j) {
  C[i][j] = 0;
  for(int a=0; a<8; a++) {
    if(0<=i+Dh[a] && i+Dh[a]<H && 0<=j+Dw[a] && j+Dw[a]<W && C[i+Dh[a]][j+Dw[a]] == 1) {
      dfs(i+Dh[a], j+Dw[a]);
    }
  }
}

C++: #include <bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef pair<int, int> P;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define MOD (int) (1e9+7)
#define INF (int) 2e9

bool seen[50*50];
vector<int> edges[50*50];

void dfs(int s, int p){
    seen[s] = true;
    for (auto v: edges[s]){
        if(v==p) continue;
        if(!seen[v]) dfs(v, s);
    }
}


int main(){
    int w, h;
    int di[8] = {-1, -1, -1, 0, 0, 1, 1, 1};
    int dj[8] = {-1, 0, 1, -1, 1, -1, 0, 1};
    
    while(true){
        cin >> w >> h;
        if(w==0 && h==0) break;
        int c[h][w];
        rep(i, h){
            rep(j, w){
                cin >> c[i][j];
                edges[w*i+j] = {};
            }
        }

        // 隣接リスト構築
        rep(i, h){
            rep(j, w){
                if(c[i][j]==1){
                    rep(k, 8){
                        int i_ = i+di[k];
                        int j_ = j+dj[k];
                        if(i_>=0 && i_<h && j_>=0 && j_<w && c[i_][j_]==1){
                            int idx = w * i_ + j_;
                            edges[w*i+j].emplace_back(idx);
                            // edges[idx].emplace_back(w*i+j);
                        }
                    }
                }
            }
        }

        rep(i, h){
            rep(j, w){
                seen[w*i+j] = false;
            }
        }

        // ここからdfs実行
        int cnt = 0;
        rep(i, h){
            rep(j, w){
                int num = w*i+j;
                if(c[i][j]==1 && !seen[num]){
                    dfs(num, -1);
                    cnt++;
                }
            }
        }
        cout << cnt << endl;
    }

    // printf("%d\n", N);
    return 0;
}

C++: #include<iostream>
#include<cstdlib>
#include<cstring>
#include<stack>
#include<queue>
#include<algorithm>
#include<vector>
#include<math.h>
#include<bitset>
#include<iomanip>
#include<numeric>
using namespace std;

typedef stack<int> IntStack;
typedef queue<int> IntQueue;

const double pi = 3.141592653589793;


//最大公約数
template<class T> T gcd(T a, T b)
{
	while (true)
	{
		T r;
		if (a%b == 0) return b;
		else
		{
			r = a % b;
			a = b;
			b = r;
		}
	}
}
//最小公倍数
template<class T> T lcm(T a, T b)
{
	return a / gcd(a, b)*b;
}
//文字0~9をint型0~9に変換
int char_to_int(char c)
{
	if (c == '0') return 0;
	if (c == '1') return 1;
	if (c == '2') return 2;
	if (c == '3') return 3;
	if (c == '4') return 4;
	if (c == '5') return 5;
	if (c == '6') return 6;
	if (c == '7') return 7;
	if (c == '8') return 8;
	if (c == '9') return 9;
	else return -1;
}
//a^b mod MODを計算
long long int ModPower(long long int a, long long int b, long long int MOD)
{
	if (b == 0) return 1;
	else if (b % 2 == 0)
	{
		long long int d = ModPower(a, b / 2, MOD);
		return (d*d) % MOD;
	}
	else
	{
		return (a*ModPower(a, b - 1, MOD)) % MOD;
	}
}
//nCr mod MODを計算
long long int ModCombi(long long int n, long long int r, long long int MOD)
{
	if (n == 0 || r == 0) return 1;

	long long int Kn = 1, Kr = 1, Knr = 1;

	long long int temp = 1;
	for (long long int i = 1; i <= n; i++)
	{
		temp *= i;
		temp %= MOD;
		if (i == n) Kn = temp;
		if (i == r) Kr = temp;
		if (i == n - r) Knr = temp;
	}

	long long int x = ModPower(Kr, MOD - 2, MOD);
	long long int y = ModPower(Knr, MOD - 2, MOD);

	long long int ans;
	ans = Kn * x;
	ans %= MOD;
	ans *= y;
	ans %= MOD;

	return ans;
}
//int型10進数をord桁のstring型2進数に変換する
string binary(int x,int ord)
{
	int y;
	string ans = "";
	for (int i = 0; i < ord; i++)
	{
		y = x / pow(2, ord - 1 - i);
		y %= 2;
		if (y == 0) ans += "0";
		else ans += "1";
	}

	return ans;
}


/*ここまでテンプレ*//*ここまでテンプレ*//*ここまでテンプレ*//*ここまでテンプレ*/

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

int d[3] = { -1,0,1 };

void dfs(int x, int y)
{
	field[x][y] = 0;

	for (int i = 0; i < 3; i++)
	{
		for (int j = 0; j < 3; j++)
		{
			int nx = x + d[i];
			int ny = y + d[j];
			if (0 <= nx && nx < H && 0 <= ny && ny < W&&field[nx][ny] == 1) dfs(nx, ny);
		}
	}
}

int main()
{
	while (true) {
		cin >> W >> H;

		if (H == 0 && W == 0) break;

		for (int i = 0; i < H; i++)
		{
			for (int j = 0; j < W; j++)
			{
				cin >> field[i][j];
			}
		}

		int ans = 0;

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

		cout << ans << endl;
	}

	return 0;
}