Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

var (
	readString func() string
	readBytes  func() []byte
	stdout     *bufio.Writer
)

func init() {
	readString, readBytes = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) (func() string, func() []byte) {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), math.MaxInt32)
	r.Split(bufio.ScanWords)

	f1 := func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
	f2 := func() []byte {
		return []byte(f1())
	}
	return f1, f2
}

func readInt() int {
	return int(readInt64())
}

func readInt64() int64 {
	i, err := strconv.ParseInt(readString(), 10, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(readString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

func printf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(stdout, f, args...)
}

func println(args ...interface{}) (int, error) {
	return fmt.Fprintln(stdout, args...)
}

func eprintln(args ...interface{}) (int, error) {
	return fmt.Fprintln(os.Stderr, args...)
}

func eprintf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(os.Stderr, f, args...)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func min64(a, b int64) int64 {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func max64(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func abs64(a int64) int64 {
	if a < 0 {
		return -a
	}
	return a
}

func gcd(a, b int) int {
	if b == 0 {
		return a
	}
	return gcd(b, a%b)
}

func gcd64(a, b int64) int64 {
	if b == 0 {
		return a
	}
	return gcd64(b, a%b)
}

// readString() string
// readInt() int
// readInt64() int64
// readFloat64() float64

// -----------------------------------------------------------------------------

func main() {
	defer stdout.Flush()

	for {
		ans, ok := solve()
		if !ok {
			break
		}
		println(ans)
	}

}

func solve() (int, bool) {
	w := readInt()
	h := readInt()
	if w == 0 && h == 0 {
		return 0, false
	}

	c := make([][]int, h+2)
	c[0] = make([]int, w+2)
	c[h+1] = make([]int, w+2)
	for i := 1; i-1 < h; i++ {
		c[i] = make([]int, w+2)
		for j := 1; j-1 < w; j++ {
			c[i][j] = readInt()
		}
	}

	var ans int
	for i := 1; i-1 < h; i++ {
		for j := 1; j-1 < w; j++ {
			if 0 < c[i][j] {
				ans++
				dfs(c, i, j)
			}
		}
	}
	return ans, true
}

func dfs(c [][]int, y, x int) {
	c[y][x] = 0
	dx := []int{-1, 0, 1, -1, 1, -1, 0, 1}
	dy := []int{-1, -1, -1, 0, 0, 1, 1, 1}
	for i := range dx {
		nx := x + dx[i]
		ny := y + dy[i]
		if 0 < c[ny][nx] {
			dfs(c, ny, nx)
		}
	}
}

// -----------------------------------------------------------------------------

C++: #include<iostream>
#include<vector>
#include<algorithm>
#include<cctype>
#include<utility>
#include<string>
#include<cmath>

#define REP(i, n) for(int i = 0;i < n;i++)
#define REPR(i, n) for(int i = n;i >= 0;i--)
#define FOR(i, m, n) for(int i = m;i < n;i++)
#define FORR(i, m, n) for(int i = m;i >= n;i--)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define llong long long
#define pb(a) push_back(a)
#define INF 999999999
using namespace std;
typedef pair<int, int> P;
typedef pair<llong, llong> LP;
typedef pair<int, P> PP;
typedef pair<llong, LP> LPP;


int w,h;
int dx[4] = {0, 1, 0, -1}, dy[4] = {-1, 0, 1, 0};

void dfs(vector<vector<int> > &map,int x,int y){
    /*for(int i = 0;i < h; i++){
        for(int j = 0; j < w; j++){
            cout << map[i][j] << " " ;
        }
        cout << endl;
    }*/
    //今いるところを-100に置き換える
    map[x][y] = -100;
    //移動方向をループ
    for(int dx = -1;dx <= 1;dx++){
        for(int dy = -1;dy <= 1;dy++){
            //x方向にdx,ｙ方向にdy移動した場所を(nx,ny)とする
            int nx = x + dx, ny = y + dy;
            if(0 <= nx && nx < h && 0 <= ny && ny < w && map[nx][ny] == 1){
                dfs(map,nx,ny);
            }
        }
    }
    return;
}

int solve(vector<vector<int> > &map,int h,int w){

    /*for(int i = 0;i < h; i++){
        for(int j = 0; j < w; j++){
            cout << map[i][j] << " " ;
        }
        cout << endl;
    }*/

    int ans = 0;
    for(int i = 0;i < h;i++){
        for(int j = 0;j < w;j++){
            if(map[i][j] == 1){
                //Wが残っているならばその場所からdfsを始める
                dfs(map,i,j);
                //ここで1つの水たまりが見つかったことになるので水たまりの個数を１つ足す
                ans++;
            }
        }
    }
    return ans;
}

int main(){

    
    

    while(cin >> w >> h){

        if(w == 0 && h == 0){
            break;
        }
        int ans = 0;
        vector<vector<int> > map(h,vector<int>(w));//周波数ベクトル列データ用の2次元配列

        for(int i = 0;i < h; i++){
            for(int j = 0; j < w; j++){
                cin >> map[i][j];
                //cout << map[i][j] << " " ;
            }
            //cout << endl;
        }
        //cout << endl;

        ans = solve(map,h,w);

        cout << ans << endl;
    }

   


    

    return 0;
}

C++: #include<iostream>
#include<cstring>
using namespace std;
bool used[55][55];
int n,m;

void check(int x,int y){
	if(x<0 || n<=x || y<0 || m<=y)return;
	if(used[x][y])return;
	used[x][y]=true;
	for(int i=-1;i<=1;i++){
		for(int j=-1;j<=1;j++){
			check(x+i,y+j);
		}
	}
}

int main(){
	int i,j,k;
	int a,b,c;
	while(cin>>m>>n){
		if(!n)break;
		memset(used,false,sizeof(used));
		for(i=0;i<n;i++){
			for(j=0;j<m;j++){
				cin>>a;
				if(a==0)used[i][j]=true;
			}
		}
		a=0;
		for(i=0;i<n;i++){
			for(j=0;j<m;j++){
				if(!used[i][j])check(i,j),a++;
			}
		}
		cout<<a<<endl;
	}
}

C++: //
// Created by elegant-belltree on 15/06/03.
//

#include <iostream>
#include <set>

using namespace std;

int main(){
    int w,h;
    int c[50][50];

    while (cin>>w>>h && (w>0 || h>0)) {
        int label=2;
        set<int> labels;

        for (int n = 0; n < 2; ++n) {
            for (int i = 0; i < h; ++i) {
                for (int j = 0; j < w; ++j) {
                    if(n==0) {
                        cin >> c[j][i];
                    }
                    if (0<c[j][i]) {
                        for (int k = -1; k < n+1 && i+k<h; ++k) {
                            for (int l = -1; (n!=0 || k!=0 || l!=0) && l < 2 && j + l < w; ++l) {
                                if (-1 < i + k && -1 < j + l && 0 < c[j + l][i + k] && (c[j][i] == 1 || c[j + l][i + k] < c[j][i])) {
                                    if(n==1){
                                        labels.erase(c[j][i]);
                                    }
                                    c[j][i] = c[j + l][i + k];
                                }
                            }
                        }
                        if (c[j][i] == 1) {
                            c[j][i] = label++;
                            labels.insert(c[j][i]);
                        }
                    }
                }
            }
        }
        /*for (int m = 0; m < h; ++m) {
            for (int i = 0; i < w; ++i) {
                cout<<c[i][m]<<" ";
            }
            cout<<endl;
        }*/
        cout<<labels.size()<<endl;
    }
    return 0;
}