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>
using namespace std;

int w,h;
int field[51][51];
void dfs(int x,int y);

int main(){
	while(cin>>w>>h&&w!=0&&h!=0){
		for(int y=0;y<h;y++){
			for(int x=0;x<w;x++){
				cin>>field[y][x];
			}
		}
		int count=0;
		for(int y=0;y<h;y++){
			for(int x=0;x<w;x++){
				if(field[y][x]==1){
					dfs(x,y);
					count++;
				}
			}
		}
		cout<<count<<endl;
	}

}

void dfs(int x,int y){
	field[y][x]=-1;
	for(int i=-1;i<=1;i++){
		for(int j=-1;j<=1;j++){
			int mx=x+i;
			int my=y+j;

			if(mx<0||my<0||mx>=w||my>=h)continue;
			if(field[my][mx]==1){
				dfs(mx,my);
			}
		}
	}
}

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

char c[102][102];

int mx, my;

void dfs(int x, int y){
    if(x < 0 || y < 0 || x >= mx || y >= my){
        return;
    }
    if(c[x][y] == '0'){
        return;
    }
    c[x][y] = '0';
    dfs(x+2, y);
    dfs(x+2, y+1);
    dfs(x+2, y-1);
    dfs(x-2, y);
    dfs(x-2, y+1);
    dfs(x-2, y-1);
    dfs(x, y+1);
    dfs(x, y-1);
    return;
}

int main(){
    int W, H, cnt = 0;
    scanf("%d %d\n", &W, &H);
    while(W != 0 || H != 0){
        mx = H;
        my = W;
        for(int k = 0; k < H; k++){
            scanf("%s\n", c[k]);
        }
        for(int i = 0; i < H; i++){
            for(int j = 0; j < W; j++){
                if(c[i][j] == '1'){
                    cnt++;
                    dfs(i, j);
                }
            }
        }
        cout << cnt << endl;
        scanf("%d %d\n", &W, &H);
        cnt = 0;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
#define rep(i, n) REP(i, 0, n)
#define REP(i, s, e) for(int i = (s); i < (int)(e); i++)
#define repr(i, n) REPR(i, n, 0)
#define REPR(i, s, e) for(int i = (int)(s - 1); i >= (int)(e); i--)
#define pb push_back
#define all(r) r.begin(), r.end()
#define rall(r) r.rbegin(), r.rend()
#define fi first
#define se second

typedef long long ll;
typedef vector<int> vi;
typedef vector<ll> vl;
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;

const ll INF = 1e18;
const ll MOD = 1e9 + 7;
const double EPS = 1e-8;

template <typename T> T chmax(T &a, const T &b) { return a = (a > b ? a : b); }
template <typename T> T chmin(T &a, const T &b) { return a = (a < b ? a : b); }

struct UF { // O(loga(n))
    int n;
    int m;
    vi d, r;
    UF(int n) : n(n), m(n), d(n, -1), r(n, 0){};
    int root(int i) {
        if(d[i] < 0) return i;
        return d[i] = root(d[i]);
    }
    bool same(int x, int y) { return root(x) == root(y); }
    bool unite(int x, int y) {
        x = root(x);
        y = root(y);
        if(x == y) return false;

        if(r[x] < r[y])
            swap(x, y);
        else if(r[x] == r[y])
            r[x]++;
        d[x] += d[y];
        d[y] = x;
        --m;
        return true;
    }
    int size(int i) { return -d[root(i)]; }
    int size() { return m; }
};

int main() {
    int w, h;
    while(cin >> w >> h) {
        if(w == 0 && h == 0) break;
        vector<vi> d(h, vi(w));
        rep(i, h) rep(j, w) cin >> d[i][j];
        UF uf(h * w);
        rep(i, h) rep(j, w) {
            if(d[i][j]) REP(dy, -1, 2) REP(dx, -1, 2) {
                int x = j + dx, y = i + dy;
                if(min(x, y) < 0 || x >= w || y >= h || d[y][x] == 0)
                    continue;
                uf.unite(i * w + j, y * w + x);
            }
        }
        int ans = 0;
        rep(i, h) rep(j, w) if(d[i][j] && uf.root(i * w + j) == i * w + j) {
            ++ans;
            // cout << " " << i << " " << j << endl;
        }
        cout << ans << endl;
    }
    return 0;
}

C++: # include <iostream>

const int MAX_W = 50;
const int MAX_H = 50;

int w, h;

int c[MAX_H][MAX_W];

int dx[8] = { 0,-1,-1,-1,0,1,1,1 }, dy[8] = { -1,-1,0,1,1,1,0,-1 };

void dfs(int x, int y) {
	c[y][x] = 0;
	for (int i = 0; i < 8; ++i) {
		int nx = x + dx[i];
		int ny = y + dy[i];
		if (nx<0 || ny<0 || nx>w || ny>h)
			continue;
		if (c[ny][nx])
			dfs(nx, ny);
	}
}

int solve() {
	int sum = 0;
	for (int i = 0; i < h; ++i) {
		for (int j = 0; j < w; ++j) {
			if (c[i][j] == 1) {
				dfs(j, i);
				++sum;
			}
		}
	}
	return sum;
}

int main() {
	while (1) {
		
		std::cin >> w >> h;
		if ((w + h) == 0)
			break;
		for (int i = 0; i < h; ++i) {
			for (int j = 0; j < w; ++j)
				c[i][j] = 0;
		}
		for (int i = 0; i < h; ++i) {
			for (int j = 0; j < w; ++j)
				std::cin >> c[i][j];
		}
		std::cout << solve() << std::endl;
	}
	return 0;
}