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 <cstdio>
#include <cstdlib>
#include <cmath>
#include <climits>
#include <cfloat>
#include <utility>
#include <memory>
#include <functional>
#include <deque>
#include <cctype>
#include <numeric>
#include <ctime>
#include <bitset>
#include <cctype>
#include <vector>
#include <map>
#include <set>
#include <stack>
#include <queue>
#include <cstring>
#include <string>
#include <sstream>
#include <algorithm>
#include <iomanip>

using namespace std;

//define
#define debug(x) cerr << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << endl;
#define dump(x)  cerr << #x << " = " << (x) << endl;

#define INF (INT_MAX/3)
#define PI (2*acos(0.0))
#define EPS (1e-8)
#define MOD (1000000007LL)

typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

typedef vector<int> vint;
typedef vector<vector<int> > vvint;
typedef vector<ll> vll;
typedef vector<vector<ll> > vvll;

#define vv(t) vector< vector< T > >
#define pb push_back
#define pu push
#define fi first
#define sec second
#define SORT(x) sort((x).begin(),(x).end())
#define EQ(a,b) (abs((a)-(b))<EPS)

int w, h;
char field[50][50];
typedef pair<int, int> P;

void bfs(int sh, int sw){
  queue<P> que;
  que.push(P(sh, sw));
  while(!que.empty()){
    P p = que.front();
    que.pop();
    int nh = p.first, nw = p.second;
    field[nh][nw] = '0';
    for(int i = -1; i <= 1; i++){
      for(int j = -1; j <= 1; j++){
        if(i == 0 && j == 0) continue;
        int th = nh + i, tw = nw + j;
        if(th < 0 || th >= h || tw < 0 || tw >= w || field[th][tw] != '1') continue;
        que.push(P(th, tw));
      }
    }
  }
}

int main(void){
  ios_base::sync_with_stdio(0);
  while(cin >> w >> h, w || h){
    for(int i = 0; i < h; i++){
      for(int j = 0; j < w; j++) cin >> field[i][j];
    }
    int ans = 0;
    for(int i = 0; i < h; i++){
      for(int j = 0; j < w; j++){
        if(field[i][j] == '0') continue;
        bfs(i, j);
        ans++;
      }
    }
    cout << ans << endl;
  }
  return 0; 
}

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

struct mapst {
	int x, y;
};

#define func(x,y) (c[y][x]&&!f[y][x])

int main() {
	int w, h, ans=0;
	int c[50][50], f[50][50];
	queue<mapst> q;
	while(1) {
		cin >> w >> h;
		if(!w&&!h) break;
		ans = 0;
		for(int i=0; i<h; ++i) for(int j=0; j<w; ++j) {
			cin >> c[i][j];
			f[i][j] = 0;
		}
		for(int i=0; i<h; ++i) for(int j=0; j<w; ++j) {
			mapst m = {j, i}, ms;
			if(func(j,i)) {
				q.push(m);
				ans++;
				do {
					m = q.front();
					q.pop();
					
					f[m.y][m.x] = 1;
					if(m.x>0&&m.y>0) if(func(m.x-1,m.y-1)) {
						ms.x = m.x-1; ms.y = m.y-1;
						q.push(ms);
					}
					if(m.y>0) if(func(m.x,m.y-1)) {
						ms.x = m.x; ms.y = m.y-1;
						q.push(ms);
					}
					if(m.x<w-1&&m.y>0) if(func(m.x+1,m.y-1)) {
						ms.x = m.x+1; ms.y = m.y-1;
						q.push(ms);
					}
					if(m.x<w-1) if(func(m.x+1,m.y)) {
						ms.x = m.x+1; ms.y = m.y;
						q.push(ms);
					}
					if(m.x<w-1&&m.y<h-1) if(func(m.x+1,m.y+1)) {
						ms.x = m.x+1; ms.y = m.y+1;
						q.push(ms);
					}
					if(m.y<h-1) if(func(m.x,m.y+1)) {
						ms.x = m.x; ms.y = m.y+1;
						q.push(ms);
					}
					if(m.x>0&&m.y<h-1) if(func(m.x-1,m.y+1)) {
						ms.x = m.x-1; ms.y = m.y+1;
						q.push(ms);
					}
					if(m.x>0) if(func(m.x-1,m.y)) {
						ms.x = m.x-1; ms.y = m.y;
						q.push(ms);
					}
				}while(!q.empty());
			}
		}
		cout << ans << endl;
	}
}

C++: #include <iostream>
#include <map>
// #include <cstdio>
#include <stacK>

using namespace std;

int main() {
	while(1) {
	int w, h, data[52][52]={{0}};
	cin >> w >> h;
	if (w == 0 && h ==0) break;
	// memset(data, 0, sizeof(data));
	for (int i=1; i<=h; i++) {
		for (int j=1; j<=w; j++) {
			cin >> data[i][j];
		}
	}
	// for (int i=0; i<h; i++) {
	// 	for (int j=0; j<w; j++) {
	// 		cout << data[i][j] << "," ;
	// 	}cout <<endl;
	// }
	stack<pair<int, int> > s;
	int count=0;
	int H[8] = {-1, -1, -1, 0, 0, 1, 1, 1}, W[8] ={-1, 0, 1, -1, 1, -1, 0, 1};
	for(int i=1; i<=h; i++) {
		for (int j=1; j<=w; j++) {
			if (data[i][j]) {
				count++;
				s.push(make_pair(i, j));
				while (!(s.empty())) {
					pair<int, int> now;
					now = s.top();
					s.pop();
					data[now.first][now.second]=0;
					for (int k=0; k<8; k++) {
						if (data[H[k]+now.first][W[k]+now.second])
							s.push(make_pair(H[k]+now.first, W[k]+now.second));
					}
				}
			}
		}
	}
	cout << count <<endl;
}
}