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"
#include "math.h"
 
using namespace std;
typedef long long ll;
typedef vector<ll> vll;
typedef vector<vll> vvll;
typedef vector<bool> vb;
typedef vector<vb> vvb;
typedef vector<int> vin;
typedef pair<ll,ll> P;
typedef vector<P> vp;
#define rep(i,a,b) for(ll i=(a);i<(b);++i)
#define SIZE(a) int((a).size())
#define out(a) cout<<(a)<<endl;
const int INF=INT_MAX;
const int MAX = 510000;
const ll MOD = 1000000007;
vin dx={-1,0,1},dy={-1,0,1};
ll w,h;
void dfs(vvll g,vvll &c,ll x,ll y){
  c[x][y]=1;
  rep(k,0,3){
    ll nx=x+dx[k];
    if(nx>=h||nx<0){continue;}
    rep(l,0,3){
      ll ny=y+dy[l];
      if(ny>=w||ny<0){continue;}
      if(!c[nx][ny]&&g[nx][ny]){
        dfs(g,c,nx,ny);
      }
    }
  }
}
int main(){
  do{
    ll cnt=0;
    cin>>w>>h;
    if(w==0&&h==0){break;}
    vvll g(h,vll(w)),c(h,vll(w,0));
    rep(i,0,h){
      rep(j,0,w){
        cin>>g[i][j];
      }
    }
    rep(i,0,h){
      rep(j,0,w){
        if(!c[i][j]&&g[i][j]){
          dfs(g,c,i,j);
          cnt++;
        }
      }
    }
   out(cnt);
  }while(w!=0&&h!=0);
}

C++: #include <bits/stdc++.h>
using namespace std;
#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 ALL(v) v.begin(), v.end()
#define CMAX(m, x)  m = max(m,x);
#define CMIN(m, x)  m = min(m,x);
#define itn int
typedef long long lint;
typedef long double ldouble;
const int INF = 1e9;
const lint LINF = 1e18;

int cnt = 0;
bool dfs(vector<vector<int> > &bi, vector<vector<int> > &flag,int x, int y){
    bool re = false;
    if(bi[y][x] == 1){
        if(flag[y][x] == 0){
            flag[y][x] = cnt;
            re = true;
            for(int i = -1;i <= 1; i++){
                for(int j = -1; j <= 1; j++){
                    dfs(bi,flag,x + i,y + j);
                }
            }
        }
    }
    return re;
}
int main(){
    int w, h;
    vector<int> ans;
    while(1){
        cin >> w >> h;
        if(w == 0 && h == 0)
            break;
        w += 2;
        h += 2;
        vector<vector<int> > bi(h,vector<int>(w));
        vector<vector<int> > flag(h,vector<int>(w,0));
        REP(i,h - 2){
            REP(j,w - 2)
                cin >> bi[i + 1][j + 1];
        }
        REP(i,h){
            bi[i][0] = 0;
            bi[i][w -1] = 0;
        }
        REP(i,w){
            bi[0][i] = 0;
            bi[h - 1][i] = 0;
        }
        REP(i,h){
            REP(j,w){
                if(bi[i][j] == 1 && flag[i][j] == 0){
                    cnt++;
                    if(!dfs(bi,flag,j,i)) cnt --;
                }
            }
        }
        ans.push_back(cnt);
        cnt = 0;
    }
    
    REP(i,ans.size())
        cout << ans[i] << endl;
    return 0;
}