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> // cout, endl, cin
#include <string> // string, to_string, stoi
#include <vector> // vector
#include <algorithm> // min, max, swap, sort, reverse, lower_bound, upper_bound
#include <utility> // pair, make_pair
#include <tuple> // tuple, make_tuple
#include <cstdint> // int64_t, int*_t
#include <cstdio> // printf
#include <map> // map
#include <queue> // queue, priority_queue
#include <set> // set
#include <stack> // stack
#include <deque> // deque
#include <unordered_map> // unordered_map
#include <iomanip>
#include <unordered_set> // unordered_set
#include <bitset> // bitset
#include <cctype> // isupper, islower, isdigit, toupper, tolower
#include <math.h>
#include <cmath>
#include <stdlib.h>
#include <stdio.h>
using namespace std;
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
const int INF = 1001001000;
const int MOD = 1000000007;

long long gcd(long long a, long long b) {
    if (b == 0) return a;
    else return gcd(b, a % b);
}
long long lcm(long long a, long long b) {
    return a * b / gcd(a, b);
}

using Graph = vector<vector<int>>;
//再帰とかグラフを使うときは予めNの最大値のグローバル配列を取っておく
int N;
vector<int> E[200001];
bool shipment[15][15];
vector<bool> seen;
typedef pair<int, int> P;
int D[101];
//頂点状態を表すcolor[]において、0は未訪問、1は訪問中、2は完了を表す。
int color[101];
int find_time = 0;
char F[51][51];
int H, W;

void dfs(int x, int y) {
    F[x][y] = '0';
    for (int i = -1; i <= 1; i++) {
        for (int j = -1; j <= 1; j++) {
            int to_x = x + i; int to_y = y + j;
            if (to_x >= 0 && to_x < H && to_y >= 0 && to_y < W && F[to_x][to_y] == '1') dfs(to_x, to_y);
        }
    }
    return;
}

int main() {
    vector<int> ans;
    int output_count = 0;

    while (true) {
        cin >> H >> W; swap(H, W);
        if (H == 0 && W == 0) {
            break;
        }
        output_count++;
        for (int i = 0; i < H; i++) {
            for (int k = 0; k < W; k++) cin >> F[i][k];
        }
            int count = 0;
            for (int i = 0; i < H; i++) {
                for (int j = 0; j < W; j++) {
                    if (F[i][j] == '1') {
                        dfs(i, j);
                        count++;
                    }
                }
            }
            ans.push_back(count);
        
    }

    for (int i = 0; i < output_count; i++) cout << ans.at(i) << endl;
}

C++: #include<iostream>

using namespace std;

bool 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]){
				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]]){
				loop(x+dx[i],y+dy[j]);
			}
		}
	}
	return ;
}

C++: #include <bits/stdc++.h>

using namespace std;

int W, H;
int f[55][55];
const int dx[] = {-1, -1, -1, +0, +0, +1, +1, +1};
const int dy[] = {-1, +0, +1, -1, +1, -1, +0, +1};

void dfs(int x, int y)
{
    f[y][x] = 0;
    for (int i = 0; i < 8; i++) {
        int nx = x + dx[i];
        int ny = y + dy[i];
        if (0 <= nx && nx < W && 0 <= ny && ny < H &&
            f[ny][nx] == 1) {
            dfs(nx, ny);
        }
    }
}

int main()
{
    while (cin >> W >> H, W) {
        for (int i = 0; i < H; i++) {
            for (int j = 0; j < W; j++) {
                cin >> f[i][j];
            }
        }

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

C++: #include <iostream>

using namespace std;

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

void input(void){
	cin >> W;
	cin >> H;

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

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, ny = y + dy;
			if(0 <= nx && nx < W && 0 <= ny && ny < H && field[nx][ny] == 1) dfs(nx, ny);
		}
	}

	return ;
}

int main(){
	while(1){
		int res = 0;
		input();
		if(W == 0 && H == 0) break;

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

		cout << res << endl;
	}

	return 0;
}