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 w,h,mp[50][50],
	dy[8]={-1,-1,0,1,1,1,0,-1},
	dx[8]={0,1,1,1,0,-1,-1,-1};
void func(int x,int y){
	mp[y][x]=0;
	for(int i=0;i<8;i++){
		int xx=x+dx[i],yy=y+dy[i];
		if(xx>=0&&xx<w&&yy>=0&&yy<h&&mp[yy][xx]) func(xx,yy);
	}
}
int main(void){
	while(1){
		cin>>w>>h;
		if(w==0&&h==0)break;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++) cin>>mp[i][j];
		}
		int cnt=0;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(mp[i][j]==1){
					cnt++;
					func(j,i);
				}
			}
		}
		cout<<cnt<<endl;
	}
}

C++: #include <bits/stdc++.h>
#define REP(i,n) for (int i=0;i<(n);i++)
#define FOR(i,s,e) for (int i=s;i<(e);i++)
#define All(v) (v).begin(),(v).end()
#define mp(a,b) make_pair(a,b)
#define pb(a) push_back(a)
#define chmax(x, y) x = max(x, y)
#define chmin(x, y) x = min(x, y)
#define int long long
using namespace std;
typedef long long llint;
typedef pair<int, int> P;
const int MOD = (int)1e9 + 7;
const int INF = (int)1e18 * 5;

struct UnionFind
{
    vector< int > data;
    
    UnionFind(int sz){
        data.assign(sz, -1);
    }
    
    bool unite(int x, int y){
        x = root(x), y = root(y);
        if(x == y) return false;
        if(data[x] > data[y]) swap(x, y);
        data[x] += data[y];
        data[y] = x;
        return true;
    }
    
    int root(int k){
        if(data[k] < 0) return(k);
        return (data[k] = root(data[k]));
    }
    
    int size(int k){
        return -data[root(k)];
    }
};

signed main(){
    cin.tie(0);
    ios::sync_with_stdio(false);

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

    int w, h;
    cin >> w >> h;
    while(!(w==0 && h==0)){
        vector< vector<int> > c(h+2, vector<int>(w+2));
        REP(i, h) c[i][0] = 0;
        REP(i, h) c[i][w+1] = 0;
        REP(j, w) c[0][j] = 0;
        REP(j, w) c[h+1][j] = 0;
        FOR(i, 1, h+1)FOR(j, 1, w+1) cin >> c[i][j];

        int num = 10, unite = 0;
        UnionFind UF(500);
        FOR(i, 1, h+1)FOR(j, 1, w+1){
            int tmp = 0;
            if(c[i][j] == 0) continue;
            if(c[i][j] == 1) c[i][j] = ++num;
            for(auto y: dy)for(auto x: dx){
                if(x==1 && y==1) continue;
                if(c[i+y][j+x] == 0) continue;
                if(c[i+y][j+x] == 1){
                    c[i+y][j+x] = c[i][j];
                    tmp++;
                }else if(UF.root(c[i+y][j+x]) != UF.root(c[i][j])){
                    unite++;
                    UF.unite(c[i+y][j+x], c[i][j]);
                }
            }
        }

        //FOR(i, 1, h+1)FOR(j, 1, w+1) cout << c[i][j] << (j==w ? "\n":" ");

        cout << num - 10 - unite << "\n";
        cin >> w >> h;
    }
    return 0;
}

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

int wm,hm;
vector< vector<int> > wh(50, vector<int>(50,0));

int xp[]={-1,0,1,-1,1,-1,0,1};
int yp[]={-1,-1,-1,0,0,1,1,1};

void dfs(int x,int y){
  for(int i=0;i<8;i++){
    int nx=x+xp[i];
    int ny=y+yp[i];
    if(nx>-1&&nx<wm&&ny>-1&&ny<hm&&wh[nx][ny]==1){
      //cout<<nx<<" "<<ny<<" "<<wh[nx][ny]<<endl;
      wh[nx][ny]=0;
      dfs(nx,ny);
    }
  }
}

int main(){
  while(1){
    //int wm,hm;
    int aa,bb;
    cin>>aa>>bb;
    wm=bb;
    hm=aa;
    if(wm==0&&hm==0)break;
    //vector< vector<int> > wh(wm, vector<int>(hm));
    for(int i=0;i<wm;i++){
      for(int j=0;j<hm;j++){
        int a;
        cin>>a;
        wh[i][j]=a;
      }
    }
    int ans=0;
    for(int i=0;i<hm;i++){
      for(int j=0;j<wm;j++){
        if(wh[i][j]==1){
          //cout<<"*"<<i<<" "<<j<<endl;
          wh[i][j]=0;
          dfs(i,j);
          ans++;
        }
      }
    }
    cout<<ans<<endl;
  }
  return 0;
}