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<stdio.h>
void printmap();
void draw(int x,int y);
int w,h,c[50][50];

int main(){
	int i,j;
	int count;


	scanf("%d %d",&w,&h);


	while((w!=0)&&(h!=0)){
		count=0;
	
		for(j=0;j<h;j++){
			for(i=0;i<w;i++){
				scanf("%d",&c[j][i]);
			}
		}
		//printf("\n");
		
		for(i=0;i<w;i++){
			c[h][i]=0;
		}
		for(i=0;i<h;i++){
			c[i][w]=0;
		}

		for(i=0;i<w;i++){
			for(j=0;j<h;j++){
				if(c[j][i]==1){
					count++;
					//printf("count up count=%d\n",count);
					draw(j,i);
					//printmap();
				}
			}
		}

		printf("%d\n",count);
		scanf("%d %d",&w,&h);
	}
	return 0;
}

void draw(int x,int y){
	//printf("delete %d %d\n",x,y);
	c[x][y]=0;
	if(c[x+1][y]==1){
		draw(x+1,y);
	}
	if(c[x-1][y]==1){
		draw(x-1,y);
	}
	if(c[x][y-1]==1){
		draw(x,y-1);
	}
	if(c[x][y+1]==1){
		draw(x,y+1);
	}

}

void printmap(){
	int i,j;
	for(j=0;j<h;j++){
		for(i=0;i<w;i++){
			printf("%d ",c[j][i]);
		}
		printf("\n");
	}
}

C++: #include<iostream>
#include<algorithm>
#include<string>
#include<stack>
#include<queue>
using namespace std;

int w, h;
int map[50][50];
int ans;

void Suibotu(int y, int x)
{//??¨??????????????????????±?????????¶????????°???????°´????????????
	map[y][x] = 0;
	if(x<w-1 && map[y][x+1]==1)				//???
		Suibotu(y, x+1);
	if(x<w-1 && y<h-1 && map[y+1][x+1]==1)	//??????
		Suibotu(y+1, x+1);
	if(y<h-1 && map[y+1][x]==1)				//???
		Suibotu(y+1, x);
	if(x>0 && y<h-1 && map[y+1][x-1]==1)	//??????
		Suibotu(y+1, x-1);
	if(x>0 && map[y][x-1]==1)				//???
		Suibotu(y, x-1);
	if(x>0 && y>0 && map[y-1][x-1]==1)		//??????
		Suibotu(y-1, x-1);
	if(y>0 && map[y-1][x]==1)				//???
		Suibotu(y-1, x);
	if(x<w-1 && y>0 && map[y-1][x+1]==1)	//??????
		Suibotu(y-1, x+1);
}
int main(){
	cin >> w >> h;
	while(w+h>0){
		ans = 0;
		for(int i=0; i<h; i++)
			for(int j=0; j<w; j++)
				cin >> map[i][j];
			for(int i=0; i<h; i++)
			for(int j=0; j<w; j++)
				if(map[i][j]==1){
					ans++;
					Suibotu(i, j);
				}
		cout << ans << endl;
		cin >> w >> h;
	}
	return 0;
}

C++: #include <iostream>
#include <stack>
using namespace std;
int dx[] = { -1, 0, 1, 1, 1, 0, -1, -1 };
int dy[] = { -1, -1, -1, 0, 1, 1, 1, 0 };

int main(){
	int w, h;
	while( cin >> w >> h && w && h ){
		int field[50][50];
		stack< pair<int, int> > st;
		for( int i = 0; i < h; i++ ){
			for( int j = 0; j < w; j++ ){
				cin >> field[i][j];
			}
		}
		int sum = 0;
		for( int i = 0; i < h; i++ ){
			for( int j = 0; j < w; j++ ){
				if( field[i][j] == 1 ){
					sum++;
					field[i][j] = 0;
					st.push( pair<int, int>(i, j) );
					//cout << i << ' ' << j << endl;
					while( !st.empty() ){
						//cout << st.top().second << ' ' << st.top().first << endl;
						int x0 = st.top().second;
						int y0 = st.top().first;
						st.pop();
						for( int k = 0; k < 8; k++ ){
							int x = x0 + dx[k];
							int y = y0 + dy[k];
							if( 0 <= x && x < w && 0 <= y && y < h && field[y][x] == 1 ){
								st.push( pair<int, int>(y, x) );
								field[y][x] = 0;
								//cout << y << ' ' << x << endl;
							}
						}
					}
				}
			}
		}
		cout << sum << endl;
	}
}