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 <bits/stdc++.h>
using namespace std;
int dx[8] = {1,0,-1,0,1,-1,-1,1};//右、上、左、下、右上、左上、左下、右下のつもり
int dy[8] = {0,1,0,-1,1,1,-1,-1};//実際は色々反転している。どうせ4か8方向調べるから関係ないとしている。
bool seen[60][60]={true};
int h,w;
void dfs(vector<vector<int> > &G,int i,int j){
    if(G[i][j]) seen[i][j] = true;
    for(int k=0;k<8;k++){
	int di = i + dx[k];
	int dj = j + dy[k];
	if(di < 0 || h <= di || dj < 0 || w <= dj)continue;
	
	if(seen[di][dj]==false) dfs(G,di,dj);
    }
}
int main(void){
    while(cin >> w >> h){
	if(w == 0 && h== 0) break;
	for(int i=0;i<h;i++)for(int j=0;j<w;j++) seen[i][j] = true;
	vector<vector<int> > G(h,vector<int>(w));
	for(int i=0;i<h;i++){
	    for(int j=0;j<w;j++){
		cin >> G[i][j];
		if(G[i][j]) seen[i][j] = false;
	    }
	}
	int t =0;
	for(int i=0;i<h;i++){
	    for(int j=0;j<w;j++){
		if(seen[i][j]) continue;
		dfs(G,i,j);
		t++;
	    }
	}
	cout << t << endl;
    }

    return 0;
}

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

int x,y;
int field[50][50];

void dfs(int w, int h){
	field[w][h]=0;
	for(int dy=-1; dy<=1; dy++){
		for(int dx=-1; dx<=1; dx++){
			int nx = w + dx;
			int ny = h + dy;
			if(nx>=0 && nx<x && ny>=0 && ny<y && field[nx][ny]==1)
				dfs(nx,ny);
		}
	}
	return;
}


int main(){
	while(1){
		int result = 0;
		cin >> x >> y;
		if(x == 0 && y == 0)
			break;
		for(int j=0; j<y; j++){
			for(int i=0; i<x; i++){
				cin >> field[i][j];
			}
		}
		for(int j=0; j<y; j++){
			for(int i=0; i<x; i++){
				if(field[i][j]==1){
					result++;
					dfs(i,j);
				}
			}
		}
		cout << result << endl;
	}
}

C++: #include <bits/stdc++.h>
using namespace std;
struct edge {
    int to;     // 辺の行き先
    int weight; // 辺の重み
    edge(int t, int w) : to(t), weight(w) { }
};
using Graph = vector<vector<int>>;
using dou =long double;
string yes="yes";
string Yes="Yes";
string YES="YES";
string no="no";
string No="No";
string NO="NO";

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
#define rep(i, n)         for(int i = 0; i < (int)(n); i++)
#define brep(n)           for(int bit=0;bit<(1<<n);bit++)
#define erep(i,container) for (auto i : container)
#define irep(i, n)        for(int i = n-1; i >= (int)0; i--)
#define rrep(i,m,n) for(ll i = m; i < (ll)(n); i++)
#define reprep(i,j,h,w) rep(i,h)rep(j,w)
#define all(x) (x).begin(),(x).end()
#define VEC(type,name,n) std::vector<type> name(n);rep(i,n)std::cin >> name[i];
#define pb push_back
#define pf push_front
#define lb lower_bound
#define ub upper_bound
#define fi first
#define se second
#define itn int
#define mp make_pair
#define sum(a) accumulate(all(a),0ll)
#define keta fixed<<setprecision
#define vvector(name,typ,m,n,a)vector<vector<typ> > name(m,vector<typ> (n,a))
#define vvvector(name,t,l,m,n,a) vector<vector<vector<t> > > name(l, vector<vector<t> >(m, vector<t>(n,a)));
#define vvvvector(name,t,k,l,m,n,a) vector<vector<vector<vector<t> > > > name(k,vector<vector<vector<t> > >(l, vector<vector<t> >(m, vector<t>(n,a)) ));
#define case std::cout << "Case #" <<qqq+1<<": "
#define res resize
#define as assign
#define ffor for(;;)
#define ppri(a,b) std::cout << a<<" "<<b << std::endl
#define pppri(a,b,c) std::cout << a<<" "<<b <<" "<< c<<std::endl
#define aall(x,n) (x).begin(),(x).begin()+(n)
 
typedef long long ll;
typedef pair<int,int> P;
//typedef long long T;
const int INF = 2000000000;
const ll INF64 = 922337203685477580ll;
const ll MOD = 1000000007ll;
int w,h;
void dfs(std::vector<std::vector<int> > &a,int y,int x){
    a[y][x]=0;
    rrep(i,max(0,y-1),min(y+2,h)){
        rrep(j,max(0,x-1),min(x+2,w)){
            if(y==i&&x==j)continue;
            if(a[i][j]==0)continue;
            dfs(a,i,j);
        }
    }
}
int main(){
    for(;;){
        
        std::cin >> w>>h;
        if(w==0)exit(0);
        vvector(a,int,h,w,0);
        reprep(i,j,h,w)std::cin >> a[i][j];
        int ans=0;
        reprep(i,j,h,w){
            if(a[i][j]){
                ans++;
                dfs(a,i,j);
            }
        }
        std::cout << ans << std::endl;
    }
    
    
}

C++: #include<iostream>

using namespace std;

int h, w, map[51][51];

const int vx[] = {1,0,-1,0}, vy[] = {0,1,0,-1};

void island(int _w, int _h) {
	map[_w][_h] = 2;
	for (int i = 0;i < 4;i++) {
		if (_w + vy[i] >= 1 && _w + vy[i] <= w&&_h + vx[i] >= 1 && _h + vx[i] <= h&&map[_w+vy[i]][_h+vx[i]] == 1) {
			island(_w + vy[i], _h + vx[i]);
		}
	}
}

int main() {
	while (cin >> w >> h, w + h) {
		for (int i = 1;i <= w;i++) {
			for (int j = 1;j <= h;j++) {
				cin >> map[i][j];
			}
		}
		int count = 0;
		for (int i = 1;i <= w;i++) {
			for (int j = 1;j <= h;j++) {
				if (map[i][j] == 1) {
					count++, island(i, j);
				}
			}
		}
		cout << count << endl;
		for (int i = 1;i <= w;i++)for (int j = 1;j <= h;j++)map[i][j] = -1;
	}
	return 0;
}