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 "bits/stdc++.h"
using namespace std;
#define rep(i,a,n) for(ll i=a;i<n;i++)
#define ALL(s) s.begin(),s.end()
#define P pair<int,int>
#define print(n) cout<<n<<endl
const int M=100010;
const int MOD=1000000007;
const int INF=1000000007;
using ll=long long;


int w,h;
char c[55][55];
int ddx[8]={-1,-1,-1,0,0,1,1,1};
int ddy[8]={-1,0,1,-1,1,-1,0,1};
int dx[4]={-1,0,1,0},dy[4]={0,-1,0,1};
bool used[55][55]={};
void dfs(int W,int H){
	if(W<0||W>=w||H<0||H>=h||used[W][H])return;
	used[W][H]=true;
	if(c[W][H]=='1'){
		rep(i,0,8)dfs(W+ddx[i],H+ddy[i]);
	}
}
int main(){
	while(1){
		int land=0;
		cin>>w>>h;
		if(w==0)break;
		rep(j,0,h){
			rep(i,0,w){
				cin>>c[i][j];
				used[i][j]=false;
			}
		}
		rep(j,0,h){
			rep(i,0,w){
				if(used[i][j]==false&&c[i][j]=='1'){
					dfs(i,j);
					land++;
				}
			}
		}
		print(land);
	}
	return 0;
}

C++: #include<iostream>
#include<map>
#include<vector>
#include<algorithm>
#include<cmath>
#include<climits>
#include<ctime>
#include<cstring>

#define ALL(v) (v).begin(),(v).end()
#define REP(i,p,n) for(int i=p;i<(int)(n);++i)
#define rep(i,n) REP(i,0,n)
#define DUMP(list) cout << "{ "; for(auto nth : list){ cout << nth << " "; } cout << "}" << endl;

using namespace std;

int W,H;

bool sima[52][52];
bool checkmap[52][52];

int dx[9]={-1,0,1,-1,0,1,-1,0,1};
int dy[9]={-1,-1,-1,0,0,0,1,1,1};


int saiki(int x, int y) 
{
	if(sima[x][y]==1){sima[x][y]=0;}
	else if(sima[x][y]==0){return 0;}

	rep(i,9){
		saiki(x+dx[i], y+dy[i]);
	}

	return 1;
}

int main() {

	while(cin >> W >> H) {
		int count=0;
		if (W == 0 && H == 0) { break; }

		rep(h,H) {
			rep(w,W) {
				sima[w][h] = 0;
				checkmap[w][h] = 0;
			}
		}

		rep(h,H) {
			rep(w,W) {
				cin >> sima[w+1][h+1];
			}
		}

		REP(h,1,H+1){
			REP(w,1,W+1){
				if(sima[w][h]==1){
					saiki(w,h);
					//cout << w << ":" << h << endl; 
					count++;	
				}
			}
		}
/*
	cout << "map" << endl; 

		rep(h,51){
			rep(w,51){
				cout << sima[w][h] << " ";
			}
			cout << endl;
		}


	
	cout << "checkmap" << endl; 

		rep(h,51){
			rep(w,51){
				cout << checkmap[w][h] << " ";
			}
			cout << endl;
		}
*/

		cout << count << endl;
	}

	return 0;
}

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

vector<int> route;
#define P 50
#define Q 50
char a[P+2][Q+2];


void search(int place1,int place2){
    a[place1][place2] = '0';
    if(a[place1][place2-1] == '1'){//左
        route.push_back(1);
        search(place1,place2-1);
    }
    else if(a[place1+1][place2] == '1'){//下
        route.push_back(2);
        search(place1+1,place2);
    }
    else if(a[place1][place2+1] == '1'){//右
        route.push_back(3);
        search(place1,place2+1);
    }
    else if(a[place1-1][place2] == '1'){//上
        route.push_back(4);
        search(place1-1,place2);
    }
    else if(a[place1+1][place2-1] == '1'){//左下
        route.push_back(5);
        search(place1+1,place2-1);
    }
    else if(a[place1+1][place2+1] == '1'){//右下
        route.push_back(6);
        search(place1,place2+1);
    }
    else if(a[place1-1][place2+1] == '1'){//右上
        route.push_back(7);
        search(place1-1,place2);
    }
    else if(a[place1-1][place2-1] == '1'){//左上
        route.push_back(8);
        search(place1-1,place2);
    }
    else{
        int bk = route.back();
        route.pop_back();//戻る
        if(bk == 0) return;
        else if(bk == 1)search(place1,place2+1);
        else if(bk == 2)search(place1-1,place2);
        else if(bk == 3)search(place1,place2-1);
        else if(bk == 4)search(place1+1,place2);
        else if(bk == 5)search(place1-1,place2+1);
        else if(bk == 6)search(place1-1,place2-1);
        else if(bk == 7)search(place1+1,place2-1);
        else if(bk == 8)search(place1+1,place2+1);
    }
}

int main(void){
    int ct;
    int x,y;
    while(1){
        ct = 0;
        cin >> y >> x;
        if(x == 0 & y == 0) break;
        for(int i = 0;i < x+2;i++){
            for(int j = 0;j < y+2;j++){
                if(i == 0||j == 0||i == x+1||j == y+1)a[i][j] = '0';
                else cin >> a[i][j];
                
            }
            
        }
        for(int i = 1;i < x+1;i++){
            for(int j = 1;j < y+1;j++){
                if(a[i][j] == '1'){
                    route.push_back(0);
                    search(i,j);
                    ct++;
                }
            }
        }
        cout << ct << endl;
    }
    return 0;
}

C++: #include <iostream>
#include <vector>
using namespace std;
#define MAX 50

int c[MAX][MAX];

void dfs(int w, int h, int x, int y);
int main(int argc, char const *argv[]){
    int w, h, ans;

    while (cin>>w>>h, w || h){
        ans = 0;
        for (int i = 0; i < h; i++){
            for (int j = 0; j < w; j++){
                cin>>c[i][j];
            }
        }
        for (int i = 0; i < w; i++){
            for (int j = 0; j < h; j++){
                if (c[i][j] == 1){
                    dfs(w, h, i, j);
                    ans++;
                }
            }
        }
        cout<<ans<<endl;
    }

    return 0;
}

void dfs(int w, int h, int x, int y){
    int dx[4] = {1, 0, -1, 0};
    int dy[4] = {0, 1, 0, -1};
    c[x][y] = 0;

    for (int i = 0; i < 4; i++){
        int nx = x + dx[i];
        int ny = y + dy[i];

        if (0 <= nx && nx < w && 0 <= ny && ny < h && c[nx][ny] == 1){
            dfs(w, h, nx, ny);
        }
    }
    return;
}