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
//------------------------------------------
#include <vector>
#include <list>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <bitset>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <sstream>
#include <iostream>
#include <iomanip>
#include <cstdio>
#include <cmath>
#include <cstdlib>
#include <cctype>
#include <string>
#include <cstring>
#include <ctime>
#include <fstream>
#include <complex>
#include <math.h>

using namespace std;

//conversion
//------------------------------------------
inline long toInt(string s) {int v; istringstream sin(s);sin>>v;return v;}
inline long toLong(string s) {long v; istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x) {ostringstream sout;sout<<x;return sout.str();}

//math
//-------------------------------------------
template<class T> inline T sqr(T x) {return x*x;}

//typedef
//------------------------------------------
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef pair<long, long> PLL;
typedef long long LL;
//container util
//------------------------------------------
#define ALL(a)  (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define PB push_back
#define MP make_pair
#define SZ(a) int((a).size())
#define EACH(i,c) for(typeof((c).begin()) i=(c).begin(); i!=(c).end(); ++i)
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())

//repetition
//------------------------------------------
#define FOR(i,a,b) for(int i=(a);i<(b);++i)
#define REP(i,n)  FOR(i,0,n)

//constant
//--------------------------------------------

//clear memory
#define CLR(a) memset((a), 0 ,sizeof(a))

const long double EPS = 1e-12;
const int INF = 10000;

char mp[52][52];

int dx[]={1,0,-1,0,-1,1,1,-1};
int dy[]={0,1,0,-1,-1,-1,1,1};
bool flag[52][52];

bool bfs(int s,int t){
	if(flag[s][t])return false;
	int sum=0;
	queue<PII>pi;
	pi.push(MP(s,t));
	flag[s][t]=true;
	while(!pi.empty()){
		PII p=pi.front();pi.pop();
		sum++;
		REP(i,8){
			int y=p.first+dy[i],x=p.second+dx[i];
			if(mp[y][x]=='1'&&!flag[y][x]){
				flag[y][x]=true;
				pi.push(MP(y,x));
			}
		}
	}
	return true;
}
int main(){
	int W,H;
	while(cin>>W>>H){
		if(W==0&&H==0)break;
		REP(i,52)REP(j,52){
			mp[i][j]='0';
		}
		CLR(flag);
		int y,x;
		REP(i,H)REP(j,W){
			cin>>mp[i+1][j+1];
		}
		int sum=0;
		REP(i,H)REP(j,W){
			if(mp[i+1][j+1]=='1'&&bfs(i+1,j+1))sum++;
		}
		//cout<<"!"<<y<<" "<<x<<endl;
		cout<<sum<<endl;
	}
	return 0;
}

C++: #include <iostream>
using namespace std;
int mp[51][51];
void init(){
  for(int i = 0; 51 > i; i++){
    for(int j = 0; 51 > j; j++){
      mp[i][j] == 0;
    }
  }
}
int tansa(int h,int w, int nh, int nw){
  if(mp[nh][nw] == 1)mp[nh][nw] = 0;
  if(nh != 0 && nw != 0 && mp[nh-1][nw-1] == 1)tansa(h,w,nh-1,nw-1);
  if(           nw != 0 && mp[nh  ][nw-1] == 1)tansa(h,w,nh  ,nw-1);
  if(nh!=h-1 && nw != 0 && mp[nh+1][nw-1] == 1)tansa(h,w,nh+1,nw-1);
  if(nh != 0 &&            mp[nh-1][nw  ] == 1)tansa(h,w,nh-1,nw  );
  if(nh!=h-1 &&            mp[nh+1][nw  ] == 1)tansa(h,w,nh+1,nw  );
  if(nh != 0 && nw!=w-1 && mp[nh-1][nw+1] == 1)tansa(h,w,nh-1,nw+1);
  if(           nw!=w-1 && mp[nh  ][nw+1] == 1)tansa(h,w,nh  ,nw+1);
  if(nh!=h-1 && nw!=w-1 && mp[nh+1][nw+1] == 1)tansa(h,w,nh+1,nw+1);
  return 0;
}
int main(){
  while(true){
    int w,h;cin>>w>>h;
    if(w == 0)break;
    for(int i = 0; h > i; i++){
      for(int j = 0; w > j; j++){
        cin >> mp[i][j];
      }
    }
    int ret = 0;
    for(int i = 0; h > i; i++){
      for(int j = 0; w > j; j++){
        if(mp[i][j] == 1){
          tansa(h,w,i,j);
          ret++;
        }
      }
    }
    cout << ret << endl;
    init();
  }
}