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 <iomanip>

#include <vector>
#include <map>
#include <set>
#include <queue>
#include <bitset>
#include <stack>
#include <utility>

#include <numeric>
#include <algorithm>
#include <functional>

#include <cctype>

#include <complex>
#include <string>
#include <sstream>

using namespace std;

#define all(c) c.begin(),c.end()
#define rall(c) c.rbegin(),c.rend()
#define rep(i,n) for(unsigned int i=0;i<(n);i++)
#define tr(it,container) for(typeof(container.begin()) it = container.begin(); \
                                                  it != container.end(); ++it)
#define mp(a,b) make_pair((a),(b))

typedef long long ll;
typedef complex<double> P;
const int dx[] = {1,0,-1,0};
const int dy[] = {0,-1,0,1};
const double EPS = 1e-9;
const int days[] = {31,28,31,30,31,30,31,31,30,31,30,31};
const int daysleap[] = {31,29,31,30,31,30,31,31,30,31,30,31};

const int dx2[] = {1,1,1,0,0,0,-1,-1,-1};
const int dy2[] = {1,0,-1,1,0,-1,1,0,-1};

void go(vector<vector<int> > &F,int h,int w){
    if(F[h][w]==0) return;
    F[h][w] = 0;
    for(int i=0;i<9;i++){
        go(F,h+dy2[i],w+dx2[i]);
    }
}
int main(){
    while(true){
        int w,h;
        cin >> w >> h;
        if(w==0) break;
        vector<vector<int> > F(h+2,vector<int>(w+2,0));
        for(int i=1;i<=h;i++){
            for(int j=1;j<=w;j++){
                int x;
                cin >> x;
                F[i][j] = x;
            }
        }
        int c=0;
        for(int i=0;i<h+2;i++){
            for(int j=0;j<w+2;j++){
                if(F[i][j] == 1){
                    go(F,i,j);
                    c++;
                }
            }
        }
        cout << c << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
using Graph = vector<vector<int>>;

vector<int> dx = {-1, -1, -1, 0, 1, 1, 1, 0};
vector<int> dy = {-1, 0, 1, 1, 1, 0, -1, -1}; 
int w, h;
int seen[55][55];

void dfs(const Graph &G, int x, int y){
    seen[y][x] = 1;
    for(int i = 0; i < 8; i++){
        if(x + dx[i] < 0 || x + dx[i] >= w || y + dy[i] < 0 || y + dy[i] >= h || G[y + dy[i]][x + dx[i]] == 0) continue;
        if(seen[y + dy[i]][x + dx[i]] == 1) continue;
        dfs(G, x + dx[i], y + dy[i]);
    }
}

int main(){
    while(true){
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        Graph G(h);
        for(int i = 0; i < h; i++){
            for(int j = 0; j < w; j++){
                int k; cin >> k;
                G[i].push_back(k);
            }
        }
        for(int i = 0; i < 55; i++){
          for(int j = 0; j < 55; j++){
            seen[i][j] = 0;
          }
        }
        int cnt = 0; 
        for(int l = 0; l < h; l++){
            for(int m = 0; m < w; m++){
                if(G[l][m] == 1 && seen[l][m] == 0){
                    dfs(G, m, l);
                    cnt++;
                }
            }
        }
        cout << cnt << endl;
    }
}