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 <iostream>
#include <stdio.h>
#include <vector>
#include <utility>
#include <string>
#include <algorithm>
#include <cmath>
#include <queue>
#include <cstring>
 
typedef long long ll;

#define rep(i,n) for(ll i = 0; i < n; i++)
 
using namespace std;
 
const ll INF = ll(1e18)+1;
const double PI=3.14159265358979323846;

int w,h,C[100][100], dx[8]={-1,1,0,0,-1,-1,1,1}, dy[8]={0,0,1,-1,-1,1,-1,1};
bool seen[100][100];

void dfs(int x, int y){
  seen[x][y] = true;
  rep(i,8){
    int movex = x+dx[i], movey = y+dy[i];
    if((movex<0 && w<=movex) || (movey<0 && h<=movey) || \
       seen[movex][movey] || C[movex][movey] == 0) continue;
    dfs(movex, movey);
  }
}

int main(){
  while(1){
    cin >> w >> h;
    if(!w && !h) break;
    rep(i,h) rep(j,w){
      cin >> C[i][j];
    }
    int ans = 0;
    rep(i,h) rep(j,w){
      if(seen[i][j] || C[i][j] == 0) continue;
      else{
	dfs(i,j);
	ans++;
      }
    }
    cout << ans << endl;
    memset(C, 0, sizeof(C));
    memset(seen, false, sizeof(seen));
  }
}

C++: #include<iostream>

using namespace std;
int w, h;
int c[50][50];
int dx[]={0, 0, 1, 1, 1, -1, -1, -1};
int dy[]={1, -1, 0, 1, -1, 0, 1, -1};
int used[50][50];

void rec(int i, int j){
   used[i][j]=1;
   for(int k=0; k<8; k++){
      int ni=i+dy[k];
      int nj=j+dx[k];
      if(!(0<=ni&&ni<h&&0<=nj&&nj<w)) continue;
      if(c[ni][nj]&&!used[ni][nj]) rec(ni, nj);
   }
}

int main(){

   while(1){
      cin>> w>> h;
      if(!(w||h)) break;
      for(int i=0; i<h; i++){
         for(int j=0; j<w; j++){
            cin>> c[i][j];
         }
      }

      fill((int*)used, (int*)used+50*50, 0);
      int cnt=0;
      for(int i=0; i<h; i++){
         for(int j=0; j<w; j++){
            if(c[i][j]&&!used[i][j]){
               cnt++;
               rec(i, j);
            }
         }
      }

      cout<< cnt<< endl;
   }

   return 0;
}

C++: #include <iostream>
#include <vector>
#include <stack>

using std::cin;
using std::cout;
using std::endl;

int main(void) {
	int w,h;
	cin >> w;
	cin >> h;

	while (w!=0||h!=0) {
		int count = 0;
		std::stack<int> st_x;
		std::stack<int> st_y;
		int xn,yn;
		int c;
		bool all = false;
		std::vector< std::vector<bool> > island(h+2, std::vector<bool>(w+2));
		for (int i = 0; i < h+2; i++) {
			for (int j = 0; j < w+2; j++) {
				if (i==0||i==h+1||j==0||j==w+1) {
					island[i][j] = false;
				} else {
					cin >> c;
					if (c==1) {
						island[i][j] = true;
						st_x.push(j);
						st_y.push(i);
					} else {
						island[i][j] = false;
					}
				}
			}
		}

		while (!st_x.empty()) {
			xn = st_x.top();
			yn = st_y.top();
			st_x.pop();
			st_y.pop();
			if (island[xn][yn]) {
				std::stack<int> st_xn,st_yn;
				island[xn][yn] = false;
				count++;
				st_xn.push(xn);
				st_yn.push(yn);
				while (!st_xn.empty()) {
					xn = st_xn.top();
					yn = st_yn.top();
					st_xn.pop();
					st_yn.pop();
					if (island[xn+1][yn]) {
						st_xn.push(xn+1);
						st_yn.push(yn);
						island[xn+1][yn] = false;
					}
					if (island[xn-1][yn]) {
						st_xn.push(xn-1);
						st_yn.push(yn);
						island[xn-1][yn] = false;
					}
					if (island[xn+1][yn+1]) {
						st_xn.push(xn+1);
						st_yn.push(yn+1);
						island[xn+1][yn+1] = false;
					}
					if (island[xn+1][yn-1]) {
						st_xn.push(xn+1);
						st_yn.push(yn-1);
						island[xn+1][yn-1] = false;
					}
					if (island[xn-1][yn+1]) {
						st_xn.push(xn-1);
						st_yn.push(yn+1);
						island[xn-1][yn+1] = false;
					}
					if (island[xn-1][yn-1]) {
						st_xn.push(xn-1);
						st_yn.push(yn-1);
						island[xn-1][yn-1] = false;
					}
					if (island[xn][yn+1]) {
						st_xn.push(xn);
						st_yn.push(yn+1);
						island[xn][yn+1] = false;
					}
					if (island[xn][yn-1]) {
						st_xn.push(xn);
						st_yn.push(yn-1);
						island[xn][yn-1] = false;
					}
				}
			}
		}
		cout << count << endl;

		cin >> w;
		cin >> h;
	}
		return 0;
}

C++: 
#include <cstdio>
#include <iostream>
#include <algorithm>
#include <cstdlib>
#include <cmath>
#include <vector>
#include <ctime>
#include <string>
#include <map>
#include <stack>
#include <queue>

using namespace std;

int w, h;
const int MAX = 50;
int c[MAX][MAX];


void check(int x, int y){
	c[x][y] = 0;
    for(int dx = -1; dx <= 1; dx++){
        for(int dy = -1; dy <= 1; dy++){
            if(x + dx >= 0 && x + dx <= w  && y + dy >= 0 && y + dy <= h && c[x + dx][y + dy] == 1){
            	check(x + dx, y + dy);
            } 
        }
    }
	
}

int main(void){

	for(int i = 0; i < MAX ; i++){
		for(int j = 0; j < MAX; j++){
			c[i][j] = 0;
		}
	}

	cin >> w >> h;
	while(w != 0 && h != 0){
		int ans = 0;
		for(int i = 0; i < h ; i++){
			for(int j = 0; j < w; j++){
				cin >> c[i][j];
			}
		}

		for(int i = 0; i < h ; i++){
			for(int j = 0; j < w; j++){
				if(c[i][j] == 1){
					check(i, j);
					ans++;
				}
			}
		}
		cout << ans << endl;

		cin >> w >> h;
	}
	
    return 0;
}