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 <map>
#include <set>
#include <list>
#include <cmath>
#include <queue>
#include <stack>
#include <cstdio>
#include <string>
#include <vector>
#include <complex>
#include <cstdlib>
#include <cstring>
#include <numeric>
#include <sstream>
#include <iostream>
#include <algorithm>
#include <functional>
  
#define mp       make_pair
#define pb       push_back
#define all(x)   (x).begin(),(x).end()
#define rep(i,n) for(int i=0;i<(n);i++)
  
using namespace std;
  
typedef    long long          ll;
typedef    unsigned long long ull;
typedef    vector<bool>       vb;
typedef    vector<int>        vi;
typedef    vector<vb>         vvb;
typedef    vector<vi>         vvi;
typedef    pair<int,int>      pii;
  
const int INF=1<<29;
const double EPS=1e-9;
  
const int dx[]={1,0,-1,0,1,1,-1,-1},dy[]={0,-1,0,1,1,-1,-1,1};

bool ok(std::vector<vector<int> > &map, int x, int y) {
    int H = map.size();
    int W = map[0].size();
    if (x < 0 || x >= W || y < 0 || y >= H) return false;
    return true;
}

void color(std::vector<vector<int> > &map, int i, int j) {
    if (map[i][j] == -1) return;
    map[i][j] = -1;

    for (int k = 0; k < 8; k++) {
        int px = j + dx[k];
        int py = i + dy[k];
        if (!ok(map, px, py)) continue;
        if (map[py][px] == 0) continue;
        if (map[py][px] == 1) {
            color(map, py, px);
        }
    }
}

int main(int argc, char const *argv[]) {
    int W, H;
    while(cin >> W >> H) {
        if (W == 0 && H == 0) break;
        std::vector<vector<int> > map(H, vector<int>(W, 0));
        for (int i = 0; i < H; i++) {
            for (int j = 0; j < W; j++) {
                cin >> map[i][j];
            }
        }
        int count = 0;
        for (int i = 0; i < H; i++) {
            for (int j = 0; j < W; j++) {
                if (map[i][j] == 1) {
                    count++;
                    color(map, i, j);
                }
            }
        }
        cout << count << endl;
    }
    return 0;
}

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

using namespace std;

typedef pair<int, int> pii;

int field[52][52];

int main(){
	while(true){
		int w, h;
		cin >> w >> h;
		if(w == 0 && h == 0){ break; }
		for(int x = 0; x <= w + 1; ++x){ field[0][x] = field[h + 1][x] = 0; }
		for(int y = 1; y <= h; ++y){
			field[y][0] = field[y][w + 1] = 0;
			for(int x = 1; x <= w; ++x){ cin >> field[y][x]; }
		}
		int answer = 0;
		for(int y = 1; y <= h; ++y){
			for(int x = 1; x <= w; ++x){
				if(field[y][x] == 0){ continue; }
				++answer;
				std::stack<pii> stk;
				stk.push(pii(x, y));
				while(!stk.empty()){
					pii pt = stk.top();
					stk.pop();
					if(field[pt.second][pt.first] > 0){
						field[pt.second][pt.first] = 0;
						stk.push(pii(pt.first - 1, pt.second - 1));
						stk.push(pii(pt.first - 1, pt.second));
						stk.push(pii(pt.first - 1, pt.second + 1));
						stk.push(pii(pt.first, pt.second - 1));
						stk.push(pii(pt.first, pt.second + 1));
						stk.push(pii(pt.first + 1, pt.second - 1));
						stk.push(pii(pt.first + 1, pt.second));
						stk.push(pii(pt.first + 1, pt.second + 1));
					}
				}
			}
		}
		cout << answer << endl;
	}
	return 0;
}

C++: // 2013/07/05 Tazoe

#include <iostream>
using namespace std;

void DFS(int M[52][52], int y, int x)
{
	M[y][x] = 0;

	if(M[y-1][x]==1)
		DFS(M, y-1, x);
	if(M[y-1][x+1]==1)
		DFS(M, y-1, x+1);
	if(M[y][x+1]==1)
		DFS(M, y, x+1);
	if(M[y+1][x+1]==1)
		DFS(M, y+1, x+1);
	if(M[y+1][x]==1)
		DFS(M, y+1, x);
	if(M[y+1][x-1]==1)
		DFS(M, y+1, x-1);
	if(M[y][x-1]==1)
		DFS(M, y, x-1);
	if(M[y-1][x-1]==1)
		DFS(M, y-1, x-1);
}

int main()
{
	while(true){
		int w, h;
		cin >> w >> h;

		if(w==0 && h==0)
			break;

		int M[52][52];
		for(int y=0; y<h+2; y++){
			for(int x=0; x<w+2; x++){
				M[y][x] = 0;
			}
		}

		for(int y=1; y<=h; y++){
			for(int x=1; x<=w; x++){
				cin >> M[y][x];
			}
		}

		int cnt = 0;

		for(int y=1; y<=h; y++){
			for(int x=1; x<=w; x++){
				if(M[y][x]==1){
					cnt++;
					DFS(M, y, x);
				}
			}
		}

		cout << cnt << endl;
	}

	return 0;
}