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>
using namespace std;
#include<vector>

int wm,hm;
vector< vector<int> > wh(51, vector<int>(51,0));

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;
}

C++: #include<iostream>
using namespace std;
int box[51][51];
int main(){
  int w,h,i,I,a;
  while(1){
    a=0;
    cin>>w>>h;
    if(w==0&&h==0) break;
    for(i=0;i<=h+1;i++){
      for(I=0;I<=w+1;I++){
	box[i][I]==0;
      }
    }
    for(i=1;i<=h;i++){
      for(I=1;I<=w;I++){
	cin>>box[i][I];
      }
    }
    for(i=1;i<=h;i++){
      for(I=1;I<=w;I++){
	if(box[i][I]==1){
	  kazu(i,I);
	  a++;
	}
      }
    }
    cout<<a<<endl;
  }
  return 0;
}
  void kazu(int i,int I){
    if(box[i][I+1]==1) {
      box[i][I+1]=0;
      kazu(i,I+1);
    }
    if(box[i][I-1]==1) {
      box[i][I-1]=0;
      kazu(i,I-1);
    }
    if(box[i+1][I]==1) {
      box[i+1][I]=0;
      kazu(i+1,I);
    }
    if(box[i+1][I+1]==1) {
      box[i+1][I+1]=0;
      kazu(i+1,I+1);
    }
    if(box[i+1][I-1]==1) {
      box[i+1][I-1]=0;
      kazu(i+1,I-1);
    }
    if(box[i-1][I+1]==1) {
      box[i-1][I+1]=0;
      kazu(i-1,I+1);
    }
    if(box[i-1][I-1]==1) {
      box[i-1][I+1]=0;
      kazu(i-1,I+1);
    }
    if(box[i-1][I]==1) {
      box[i-1][I]=0;
      kazu(i-1,I);
    }

  }

C++: #include<iostream>
#include<cmath>
#include<algorithm>
#include<vector>

using namespace std;


vector<vector<bool>> seen;
vector<int> dx;
vector<int> dy;

void dfs(int u,int v,vector<vector<int>> &c){

    seen[u][v]=true;

    for(int i=0;i<8;i++){
        if(c[u+dx[i]][v+dy[i]]==0)continue;
        if(seen[u+dx[i]][v+dy[i]])continue;
        dfs(u+dx[i],v+dy[i],c);
    }

}

int main(){

    dx={-1,0,1,-1,1,-1,0,1};
    dy={1,1,1,0,0,-1,-1,-1};

    int w=1,h=1;
    cin >> w >> h;
    while(true){
        if(h==0 && w==0)break;
        else{
            vector<vector<int>> c(h+2);
            for(int i=0;i<h+2;i++)c[i].resize(w+2);

            for(int i=0;i<w+2;i++)c[0][i]=0;

            for(int i=1;i<h+1;i++){
                c[i][0]=0;
                for(int j=0;j<w;j++){
                    cin >> c[i][j+1];
                }   
                c[i][w+1]=0;
            }
            for(int i=0;i<w+2;i++)c[h+1][i]=0;
            seen.resize(h+2);
            for(int i=0;i<h+2;i++)seen[i].assign(w+2,false);            

            int e=0;

            for(int i=1;i<h+1;i++){
                for(int j=1;j<w+1;j++){
                    if(seen[i][j]==false && c[i][j]==1){
                        dfs(i,j,c);
                        e++;
                    }
                }
            }
            cout << e << endl;
        }
        cin >> w >> h;
    }
}