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<algorithm>
#include<bitset>
#include<iostream>
#include<iomanip>
#include<set>
#include<string>
#include<math.h>

using namespace std;

class zahyo{
	public:
	int x;
	int y;
	zahyo(){
		x=0;
		y=0;
	}
	zahyo(int x_,int y_){
		x=x_;
		y=y_;
	}
	void print(){
		cout<<x<<" "<<y;
	}
	zahyo operator+(zahyo add){
		add.x=this->x+add.x;
		add.y=this->y+add.y;
		return add;
	}
	zahyo operator-(zahyo add){
		add.x=this->x-add.x;
		add.y=this->y-add.y;
		return add;
	}
	bool operator==(const zahyo add) const{
		if(add.x==this->x and add.y==this->y){return true;}
		else{return false;}
	}
	bool operator!=(const zahyo add) const{
		if(add.x==this->x or add.y==this->y){return false;}
		else{return true;}
	}
	bool operator<(const zahyo add) const{
		if(this->x<add.x){return true;}
		else if(this->x==add.x and this->y<add.y){return true;}
		else{return false;}
	}
	bool operator>(const zahyo add) const{
		if(this->x>add.x){return true;}
		else if(this->x==add.x and this->y>add.y){return true;}
		else{return false;}
	}
	void input(){
		cin>>x>>y;
	}
};

int n;
int counter=0;
int field[50][50]={{}};
int arrived[50][50]={{}};
int ways[8][2]={{1,1},{1,0},{1,-1},{0,-1},{-1,-1},{-1,0},{-1,1},{0,1}};
int h,w;
void depthsearch(int h_,int w_){
	arrived[h_][w_]=1;
	for(int i=0;i<8;i++){
		int newh=h_+ways[i][0];
		int neww=w_+ways[i][1];
		if(newh>=0 and newh<h and neww>=0 and neww<w){
			if(arrived[newh][neww]==0 and field[newh][neww]==1){
				depthsearch(newh,neww);
			}
		}
	}
}

int main(){

	while(1){
		cin>>w>>h;
		if(w==0 and h==0){break;}
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				cin>>field[i][j];
				arrived[i][j]=0;
			}
		}
		int ans=0;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(arrived[i][j]==0 and field[i][j]==1){
					depthsearch(i,j);
					ans++;
				}
			}
		}
		cout<<ans<<endl;
	}
}

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

void proc(int *maps,int p,int w,int h){
	if(maps[p]==1) maps[p]=2;
	else return;
	int x=p%w;
	int y=p/w;
	for(int i=-1;i<=1;++i){
		for(int j=-1;j<=1;++j){
			int nx=x+j;
			int ny=y+i;
			if(nx>=0&&ny>=0&&nx<w&&ny<h){
				proc(maps,nx+ny*w,w,h);
			}
		}
	}
}

int main(void){
	int w,h;
	while(cin>>w>>h,w&&h){
		int chizu[2500];
		for(int i=0;i<h;++i){
			for(int j=0,a;j<w;++j){
				cin>>a;
				chizu[i*w+j]=a;
			}
		}
		int count = 0;
		for(int i=0;i<w*h;++i){
			if(chizu[i]==1){
				proc(chizu,i,w,h);
				++count;
			}
		}
		cout<<count<<endl;
	}
	return 0;
}

C++: #include <iostream>

using namespace std;

int w, h;
int c[50][50];
char dx[] = {-1,-1,-1,0,1,1,1,0};
char dy[] = {-1,0,1,1,1,0,-1,-1};

void dfs(int x, int y){
	c[x][y] = 0;
	for(int i=0;i<8;i++){
		int nx = x+dx[i], ny = y+dy[i];
		if(nx<0||h<=nx||ny<0||w<=ny||!c[nx][ny]) continue;
		dfs(nx,ny);
	}
}

int main(){
	while(cin >> w >> h, w){
		for(int i=0;i<h;i++)
			for(int j=0;j<w;j++)
				cin >> c[i][j];
		int ans = 0;
		for(int i=0;i<h;i++)
			for(int j=0;j<w;j++)
				if(c[i][j]) ans++, dfs(i,j);
		cout << ans << endl;
	}
}