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>

using namespace std;

struct UFTree{
	vector<int> p;
	UFTree(int n):p(n,-1){}
	void Unite(int a,int b){
		int ra=Find(a),rb=Find(b);
		if(ra!=rb){
			if(-p[ra]<-p[rb])
				swap(ra,rb);
			p[ra]+=p[rb];
			p[rb]=ra;
		}
	}
	int Find(int n){
		return p[n]<0?n:p[n]=Find(p[n]);
	}
};

int main()
{
	for(int w,h;cin>>w>>h,w|h;){
		int grid[50][50];
		for(int i=0;i<h;i++)
			for(int j=0;j<w;j++)
				cin>>grid[i][j];
		UFTree uft(h*w);
		for(int i=0;i<h;i++)
			for(int j=0;j<w;j++){
				if(!grid[i][j])
					continue;
				int di[]={0,1,1,1},dj[]={1,-1,0,1};
				for(int k=0;k<4;k++){
					int ni=i+di[k],nj=j+dj[k];
					if(0<=ni && ni<h && 0<=nj && nj<w && grid[ni][nj])
						uft.Unite(i*w+j,ni*w+nj);
				}
			}
		int res=0;
		for(int i=0;i<h;i++)
			for(int j=0;j<w;j++)
				if(grid[i][j] && uft.p[i*w+j]<0)
					res++;
		cout<<res<<endl;
	}
	return 0;
}

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

int counter=2;
int Map[50][50];
int x[8] = {0,0,1,-1,1,1,-1,-1};
int y[8] = {-1,1,0,0,1,-1,1,-1};
int w,h;

void bfs(int xx,int yy){
  Map[yy][xx]=counter;
  queue<int> q;
  int pos = yy*w+xx;
  q.push(pos);
  while(!q.empty()){
    pos=q.front();
    q.pop();
    yy=pos/w;
    xx=pos%w;
    for(int k=0;k<8;k++){
      int a=xx+x[k];
      int b=yy+y[k];
      if(a < 0 || a >= w || b < 0 || b >= h) continue;
      if(Map[b][a]==1){
	Map[b][a]=counter;
	q.push(b*w+a);
      }
    }
  }
}

int main(){
  while(cin>>w>>h , w+h){
    counter=2;
    memset(Map,0,sizeof(Map));
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	cin>>Map[i][j];
      }
    }

    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
	if(Map[i][j]==1){
	  bfs(j,i);
	  counter++;
	  //     	  cout<<" i = "<<i<<" j = "<<j<<endl;
	}
      }
    }
    cout<<counter-2<<endl;
  }
  return 0;
}

C++: #include<queue>
#include<cstdio>

#define	mp	make_pair

using namespace std;

typedef	pair<int,int>	pii;

const int dx[]={1,1,0,-1,-1,-1,0,1},dy[]={0,-1,-1,-1,0,1,1,1};
int field[50][50];
bool visited[50][50];

int main(){
	for(int w,h;scanf("%d%d",&w,&h),w;){
		for(int i=0;i<h;i++)for(int j=0;j<w;j++){
			scanf("%d",field[i]+j);
			visited[i][j]=false;
		}

		int cnt=0;
		for(int i=0;i<h;i++)for(int j=0;j<w;j++){
			if(field[i][j]==1 && !visited[i][j]){
				visited[i][j]=true;
				queue<pii> qu;	qu.push(mp(i,j));
				while(!qu.empty()){
					pii a=qu.front();	qu.pop();
					for(int k=0;k<8;k++){
						int xx=a.second+dx[k],yy=a.first+dy[k];
						if(0<=xx && xx<w && 0<=yy && yy<h
						&& field[yy][xx]==1 && !visited[yy][xx]){
							qu.push(mp(yy,xx));
							visited[yy][xx]=true;
						}
					}
				}
				cnt++;
			}
		}

		printf("%d\n",cnt);
	}

	return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

int H, W;
vector<vector<int>> field;
void dfs(int h, int w) {
    field[h][w] = 0;
    for(int dh = -1; dh <= 1; dh++) {
        for(int dw = -1; dw <= 1; dw++) {
            int nh = h + dh;
            int nw = w + dw;
            if(nh < 0 || H <= nh || nw < 0 || W <= nw) {
                continue;
            }
            if(field[nh][nw] == 0) {
                continue;
            }
            dfs(nh, nw);
        }
    }
}
int main() {
    while (cin >> W >> H) {
        if (H == 0 || W == 0) break;
        field.assign(H, vector<int>(W, 0));
        for (int h = 0; h < H; ++h) for (int w = 0; w < W; ++w) cin >> field[h][w];

        // 探索開始
        int count = 0;
        for (int h = 0; h < H; ++h) {
            for (int w = 0; w < W; ++w) {
                if (field[h][w] == 0) continue; // 残島じゃなかったらスルー
                dfs(h, w);
                ++count;
            }
        }
        cout << count << endl;
    }
}