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<>

using namespace std;

struct Node{

	Node();

	int aLandType;

};

Node::Node(){
	aLandType = 0;
}

bool check(const int x, const int y, const int LandNum, const int aNodeCol[50][50], const int aXMax, const int aYMax){
	if ((x<0 || x >= aXMax) || (y<0 || y >= aYMax) || (aNodeCol[x][y] != 1)){
		return false;
	}
	return true;
}
bool LandConfirmedAndMawariCheck(const int x, const int y, const int LandNum, int aNodeCol[50][50], const int aXMax, const int aYMax){
	if (aNodeCol[x][y] == 1){
		aNodeCol[x][y] = LandNum;
		/*if (check(x - 1, y, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x - 1, y, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x - 1, y - 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x - 1, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x - 1, y + 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x - 1, y + 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x + 1, y - 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x + 1, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x + 1, y, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x + 1, y, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x + 1, y + 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x + 1, y + 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x, y - 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (check(x, y + 1, LandNum, aNodeCol, aXMax, aYMax))LandConfirmedAndMawariCheck(x, y + 1, LandNum, aNodeCol, aXMax, aYMax);*/
		if (!(x - 1<0 || x - 1 >= aXMax) || (y    <0 || y     >= aYMax) || (aNodeCol[x-1][y    ] != 1))LandConfirmedAndMawariCheck(x - 1, y    , LandNum, aNodeCol, aXMax, aYMax);
		if (!(x - 1<0 || x - 1 >= aXMax) || (y - 1<0 || y - 1 >= aYMax) || (aNodeCol[x-1][y - 1] != 1))LandConfirmedAndMawariCheck(x - 1, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x - 1<0 || x - 1 >= aXMax) || (y + 1<0 || y + 1 >= aYMax) || (aNodeCol[x-1][y + 1] != 1))LandConfirmedAndMawariCheck(x - 1, y + 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x + 1<0 || x + 1 >= aXMax) || (y - 1<0 || y - 1 >= aYMax) || (aNodeCol[x+1][y - 1] != 1))LandConfirmedAndMawariCheck(x + 1, y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x + 1<0 || x + 1 >= aXMax) || (y    <0 || y     >= aYMax) || (aNodeCol[x+1][y    ] != 1))LandConfirmedAndMawariCheck(x + 1, y    , LandNum, aNodeCol, aXMax, aYMax);
		if (!(x + 1<0 || x + 1 >= aXMax) || (y + 1<0 || y + 1 >= aYMax) || (aNodeCol[x+1][y + 1] != 1))LandConfirmedAndMawariCheck(x + 1, y + 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x    <0 || x     >= aXMax) || (y - 1<0 || y - 1 >= aYMax) || (aNodeCol[x  ][y - 1] != 1))LandConfirmedAndMawariCheck(x    , y - 1, LandNum, aNodeCol, aXMax, aYMax);
		if (!(x    <0 || x     >= aXMax) || (y + 1<0 || y + 1 >= aYMax) || (aNodeCol[x  ][y + 1] != 1))LandConfirmedAndMawariCheck(x    , y + 1, LandNum, aNodeCol, aXMax, aYMax);
		return true;
	}
	return false;
}

C++: #include<bits/stdc++.h> 
using namespace std;
using ll=long long;
typedef pair<int,int> P;
#define all(v) (v).begin(),v.end()
#define fi first
#define se second
const ll inf=(1e18);
const ll mod=1000000007;
bool dp[100000];
int main(){
while(1){
int w,h;
cin>>w>>h;
if(w==0||h==0)return 0;
vector<vector<int>> s(h,vector<int>(w)),a(h,vector<int>(w,-1));
for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
        cin>>s[i][j];
        if(s[i][j]==1)a[i][j]=0;
    }
}
queue<P> que;
int ans=0;
for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
        if(a[i][j]==0){
            a[i][j]=1;
            que.push(P(i,j));
            while(!que.empty()){
                P p=que.front();
                  que.pop();
                  for(int dy=-1;dy<=1;dy++){
                      for(int dx=-1;dx<=1;dx++){
                          int ny=dy+p.fi,nx=dx+p.se;
                          if(ny<0||ny>=h||nx<0||nx>=w||a[ny][nx]!=0)continue;
                          a[ny][nx]=1;
                          que.push(P(ny,nx));
                      }
                  }
            }
            ans++;
        }
    }
}
cout<<ans<<endl;
}
}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
#define rep1(i, n) for (int i = 1; i < (n); ++i)
using namespace std;
typedef long long ll;

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


int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);

    while(1){
        int w, h;
        cin >> w >> h;

        if(w==0) break;

        vector<vector<int>> c(h, vector<int>(w));
        rep(i, h) rep(j, w) cin >> c[i][j];

        int cnt = 0;
        vector<vector<int>> seen(h, vector<int>(w, 0));

        rep(i, h) rep(j, w){
            if(c[i][j] == 0) continue;
            if(seen[i][j]) continue;
            ++cnt;
            
            seen[i][j] = cnt;
            vector<pair<int, int>> stack;
            stack.push_back(make_pair(i, j));
            while(!stack.empty()){
                int x = stack.back().second;
                int y = stack.back().first;
                stack.pop_back();

                rep(dir, 8){
                    int ny = y + dy[dir];
                    int nx = x + dx[dir];

                    if(ny<0 || ny>=h || nx<0 || nx>=w) continue;
                    if(c[ny][nx] == 0) continue;
                    if(seen[ny][nx]) continue;

                    seen[ny][nx] = cnt;
                    stack.push_back(make_pair(ny, nx));
                }
            }
        }

        cout << cnt << endl;
    }

    return 0;
}