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;
typedef long long ll;
typedef long int li;
typedef long double lb;
#define rep(i,j,n) for (ll i = j; i < (n); i++)
#define repr(i,j,n) for(ll i = j; i >= (n); i--)
#define all(x) (x).begin(),(x).end()
#define CLR(mat,f) memset(mat, f, sizeof(mat))
#define IN(a, b, x) (a<=x&&x<b)
#define out(ans) cout << ans << endl
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return 1; } return 0; }
typedef pair<ll,ll>P;
const ll mod=1e9+7;
const ll INF = 1LL<<60;


ll w,h;
const ll dx[]={-1,0,1,-1,1,-1,0,1},dy[]={-1,-1,-1,0,0,1,1,1};

// void dfs(ll height,ll width,ll map[height][width],ll check[height][width]){

// }

int main(){

  while(cin>>w>>h){
    if(w==0&&h==0)break;

    ll map[h][w];
    ll check[h][w];
    rep(i,0,h){
      rep(j,0,w){
        cin>>map[i][j];
        check[i][j]=-1;
      }
    }
    ll num=0;
    rep(i,0,h){
      rep(j,0,w){
        if(map[i][j]==1&&check[i][j]==-1){
          num++;
          stack<P>s;
          s.push(P(i,j));

          while(!s.empty()){
            P p=s.top();s.pop();
            ll y=p.first,x=p.second;

            check[y][x]=num;
            rep(i,0,8){
              ll ny=y+dy[i],nx=x+dx[i];
              if(IN(0,h,ny)&&IN(0,w,nx)&&map[ny][nx]==1&&check[ny][nx]==-1){
                s.push(P(ny,nx));
              }
            }
          }
        }
      }
    }

    out(num);

  }


  return 0;
}

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

void add_label(map<int,int> &tbl, int a, int b){
	if( a == b ) return;
	if(a < b){
		int tmp = a;
		a = b;
		b = tmp;
	}
	if( tbl.find(a) == tbl.end() ) {
		tbl[a] = b;
	} else {
		int bb = tbl.find(a)->second;
		if( b == bb ) return;
		if( bb > b ) {
			tbl[a] = b;
			tbl[bb] = b;
		} else {
			tbl[b] = bb;
		}
	}
}

int main(void){
	int w, h;
	while( cin>>w>>h, w||h ) {
		vector<vector<int> > field( h );
		vector<vector<int> > labeled( h );
		for( int i=0; i<h; ++i ) {
			field[i] = vector<int>( w );
			labeled[i] = vector<int>( w );
			for( int j=0; j<w; ++j ) {
				cin>>field[i][j];
				labeled[i][j] = 0;
			}
		}
		int label = 0;
		map<int, int> tbl;
		for( int i=0; i<h; ++i ) {
			for( int j=0; j<w; ++j ) {
				if( field[i][j] ){
					bool f = false;
					if( i ) {
						if( j && labeled[i-1][j-1] ) {
							if(!f) labeled[i][j] = labeled[i-1][j-1];
							f = true;
						}
						if( labeled[i-1][j] ) {
							if(!f) labeled[i][j] = labeled[i-1][j];
							else add_label( tbl, labeled[i][j], labeled[i-1][j] );
							f = true;
						}
						if( j + 1 < w && labeled[i-1][j+1] ) {
							if(!f) labeled[i][j] = labeled[i-1][j+1];
							else add_label( tbl, labeled[i][j], labeled[i-1][j+1] );
							f = true;
						}
						if( j && labeled[i][j-1] ) {
							if(!f) labeled[i][j] = labeled[i][j-1];
							else add_label( tbl, labeled[i][j], labeled[i][j-1] );
							f = true;
						}
					} else {
						if( j && labeled[i][j-1] ){
							if(!f) labeled[i][j] = labeled[i][j-1];
							else add_label( tbl, labeled[i][j], labeled[i][j-1] );
							f = true;
						}
					}
					if(!f) labeled[i][j] = ++label;
				}
			}
		}
		for( auto x : tbl ) {
			int a = x.first;
			int b = x.second;
			while( tbl.find(b) != tbl.end() ) {
				b = tbl.find(b)->second;
			}
			for( int i=0; i<h; ++i ) {
				for( int j=0; j<w; ++j ) {
					if( labeled[i][j] == a ) labeled[i][j] = b;
				}
			}
		}
		
		/*
		for( int i=0; i<h; ++i ) {
			cerr<<"!";
			for( int j=0; j<w; ++j ) {
				cerr<<labeled[i][j];
			}
			cerr<<endl;
		}*/
		
		set<int> nums;
		nums.insert(0);
		for( int i=0; i<h; ++i ) {
			for( int j=0; j<w; ++j ) {
				nums.insert( labeled[i][j] );
			}
		}
		cout<<nums.size()-1<<endl;
	}
	return 0;
}