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>

using namespace std;

int idirs[] = {0, 0, 1, 1, 1, -1, -1, -1};
int jdirs[] = {1, -1, 0, 1, -1, 0, 1, -1};

int map[52][52];

void dfs(int i, int j) {
    if (!map[i][j]) return;
    map[i][j] = 0;
    for (int k = 0; k < 8; ++k) {
        dfs(i + idirs[k], j + jdirs[k]);
    }
}

int main() {
    while (1) {
        int w, h;

        cin >> w >> h;

        if (w == 0) break;

        for (int i = 0; i < 52; ++i)
            for (int j = 1; j < 52; ++j)
                map[i][j] = 0;

        for (int i = 1; i <= h; ++i) {
            for (int j = 1; j <= w; ++j) {
                cin >> map[i][j];
            }
        }

        int ans = 0;
        for (int i = 1; i <= h; ++i) {
            for (int j = 1; j <= w; ++j) {
                if (map[i][j] == 1) {
                    dfs(i, j);
                    ans++;
                }
            }
        }

        cout << ans << endl;
    }
}

C++: #include <iostream>
#include <stdio.h>
#include <algorithm>
#include <math.h>
#include <vector>
#include <string>
#include <sstream>
#include <numeric>
#include <set>
#include <map>
//#include <bits/stdc++.h>

#define rep(i, j) for(int i = 0; i < j; i++)
#define all(i) i.begin(), i.end()
#define ll long long
#define bl bool
#define nn printf("\n");
#define mod 1000000007

using namespace std;

int w, h, cnt = 0;

void srch(int x, int y, vector<vector<int>> &inp, vector < vector <bool>> &hit)
{
	if (x < 0 || w <= x || y < 0 || h <= y || inp[y][x] == 0) { return; }
	if (hit[y][x]) return;
	hit[y][x] = true;
	cnt += 1;
	srch(x + 1, y, inp, hit);
	srch(x - 1, y, inp, hit);
	srch(x, y + 1, inp, hit);
	srch(x, y - 1, inp, hit);
	srch(x + 1, y + 1, inp, hit);
	srch(x + 1, y - 1, inp, hit);
	srch(x - 1, y + 1, inp, hit);
	srch(x - 1, y - 1, inp, hit);
}
int main()
{
	cin.tie(0);
	ios::sync_with_stdio(false);
	while (cin >> w >> h && w != 0 && h != 0)
	{
		vector<vector<int>> inp(h, vector<int>(w, 0));
		vector<vector<bool>> hit(h, vector<bool>(w, false));
		int ans = 0;
		rep(y, h) rep(x, w){ cin >> inp[y][x]; }
		rep(y, h) rep(x, w)
		{
			srch(y, x, inp, hit);
			if (cnt > 0) { ans += 1; }
			cnt = 0;
		}
		printf("%d\n", ans);
	}

	return 0;
}

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 ;
}