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++: #define _USE_MATH_DEFINES
#include "bits/stdc++.h"
#define EPS 1e-10
using namespace std;
typedef long long llong;
vector<vector<char> >v;
int cnt;
int w, h;

bool dfs(int x, int y) {

	if (x < 0 || h <= x)return false;
	if (y < 0 || w <= y)return false;

	if (v[x][y] == '1') {
		v[x][y] = '0';
		dfs(x - 1, y - 1);
		dfs(x - 1, y);
		dfs(x - 1, y + 1);
		dfs(x, y - 1);
		dfs(x, y + 1);
		dfs(x + 1, y - 1);
		dfs(x + 1, y);
		dfs(x + 1, y + 1);
		return true;
	}

	return false;

}


int main() {
	while (cin >> w >> h, h) {
		v = vector<vector<char> >(h, vector<char>(w));
		cnt = 0;
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
			cin >> v[i][j];

			}
		}
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (dfs(i, j))cnt++;
			}
		}
		cout << cnt << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)
#define FOR(i,x,n) for(int i=x; i<(n); i++)
#define ALL(n) begin(n),end(n)
#define MOD 1000000007
#define INF 1e9
#define INFL 1e16
 
typedef long long ll;
typedef unsigned int ui;
typedef unsigned long long ull;
template<class T>using arr=vector<vector<T>>;
template<class T>void pr(T x){cout << x << endl;}
template<class T>void prvec(vector<T>& a){rep(i, a.size()-1){cout << a[i] << " ";} cout << a[a.size()-1] << endl;}
template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }
 
arr<int> land;
int ans;
int h, w;

void dfs(int x, int y){
    land[x][y] = 0;
    FOR(i, -1, 2){
        FOR(j, -1, 2){
            if(i==0 && j==0) continue;
            if(x+i < 0 || x+i >= h || y+j < 0 || y+j >= w) continue;
            if(land[x+i][y+j]==1){
                dfs(x+i, y+j);
            }
        }
    }
}

int main()
{
    while(1){
        cin >> w >> h;
        if(w==0 && h==0) break;
        land.resize(h);
        rep(i, h) land[i].resize(w);

        rep(i, h) rep(j, w) cin >> land[i][j];
        ans = 0;
        rep(i, h) rep(j, w){
            if(land[i][j]==0) continue;
            ans++;
            dfs(i, j);
        }
        pr(ans);
    }
    return 0;}

C++: #include "bits/stdc++.h"
using namespace std;

#define ASC(vec) vec.begin(), vec.end()		// 昇順ソート 例：sort(ASC(vec));
#define DESC(vec) vec.rbegin(), vec.rend()	// 降順ソート 例:sort(DESC(vec));
#define rep(i, n) for(int i = 0; i < (n); i++)
#define Rep(i, n) for(int i = 1; i < n; i++)

const int mod = 1000000007;
const int inf = (int)1e9 + 7;
const long long INF = 1LL << 60;

using ii = pair<int, int>;
using ll = long long;
using vi = vector<int>;
using vd = vector<double>;
using vb = vector<bool>;
using vl = vector<ll>;
using vs = vector<string>;
using vvi = vector<vector<int>>;
using vvl = vector<vector<ll>>;
using vvb = vector<vector<bool>>;
using vii = vector<pair<int, int>>;

template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }

ll GCD(ll a, ll b) { return b ? GCD(b, a % b) : a; }
ll LCM(ll a, ll b) { return (a * b) / GCD(a, b); }
int round_int(int a, int b) { return (a + (b - 1)) / b; }

// 素因数分解; 返り値は(素数, 乗数)のvector配列
vector<pair<ll, int>> factorize(ll n) {
	vector<pair<ll, int>> res;
	for (ll i = 2; i * i <= n; ++i) {
		if (n % i) continue;
		res.emplace_back(i, 0);
		while (n % i == 0) {
			n /= i;
			res.back().second++;
		}
	}
	if (n != 1) res.emplace_back(n, 1);
	return res;
}

constexpr array<int, 9> dx = { 0, 1, 0, -1, -1, 1, 1, -1, 0 };
constexpr array<int, 9> dy = { 1, 0, -1, 0, 1, 1, -1, -1, 0 };
constexpr auto MAX = 100000;

// ──────────────────────────────────────────────────────────────────

// UnionFind 解説：https://youtu.be/TdR816rqc3s?t=8424

int w, h, t[50][50], cnt = 0;
bool check[50][50];

void dfs(ii pos) {
	int y = pos.first;
	int x = pos.second;

	rep(i, 8) {
		int nx = x + dx[i], ny = y + dy[i];

		if (0 <= nx && nx < w &&
			0 <= ny && ny < h &&
			check[ny][nx] == false &&
			t[ny][nx] == 1) {
			check[ny][nx] = true;
			dfs({ ny,nx });
		}
	}
}

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

		if (!w && !h) break;

		cnt = 0;
		rep(i, 50) rep(j, 50) check[i][j] = false;
		rep(i, h) rep(j, w) cin >> t[i][j];

		rep(i, h) {
			rep(j, w) {
				if (t[i][j] == 1 && check[i][j] == false) {
					check[i][j] = true;
					dfs({ i, j });
					cnt++;
				}
			}
		}
		ans.push_back(cnt);
	}
	rep(i, ans.size()) cout << ans[i] << endl;
}