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 <algorithm>

using namespace std;

int tizu[52][52];

void check(int i, int j) {
	tizu[i][j] = 0;
	for (int k = -1; k <= 1; k++) {
		for (int l = -1; l <= 1; l++) {
			if (tizu[i+k][j+l] == 1) {
				check(i+k,j+l);
			}
		}
	}
	return;
}

int main() {
	int w, h;
	while (cin >> w >> h) {
		if (w == 0 && h == 0) {
			break;
		}
		for (int i = 0; i < 52; i++) {
			for (int j = 0; j < 52; j++) {
				tizu[i][j] = 0;
			}
		}
		int counter = 0;
		for (int i = 1; i <= h; i++) {
			for (int j = 1; j <= w; j++) {
				cin >> tizu[i][j];
			}
		}
		for (int i = 1; i <= h; i++) {
			for (int j = 1; j <= w; j++) {
				if (tizu[i][j] == 1) {
					counter++;
					check(i,j);
				}
			}
		}
		cout << counter << endl;
	}
	return 0;
}

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

// 入力
int H, W;
vector<vector<int> > field;

// 探索
void dfs(int h, int w) {
    field[h][w] = 0;

    // 八方向を探索
    for (int dh = -1; dh <= 1; ++dh) {
        for (int dw = -1; dw <= 1; ++dw) {
            int nh = h + dh, nw = w + dw;
            
            // 場外アウトしたり、0 だったりはスルー
            if (nh < 0 || nh >= H || nw < 0 || nw >= W) continue;
            if (field[nh][nw] == 0) continue;

            // 再帰的に探索
            dfs(nh, nw);
        }
    }
}

int main() {
    // 入力受け取り
    while (cin >> W >> H) {
        if (H == 0 || W == 0) break;
        field.assign(H, vector<int>(W, 0));
        for (int h = 0; h < H; ++h) for (int w = 0; w < W; ++w) cin >> field[h][w];

        // 探索開始
        int count = 0;
        for (int h = 0; h < H; ++h) {
            for (int w = 0; w < W; ++w) {
                if (field[h][w] == 0) continue; // 残島じゃなかったらスルー
                dfs(h, w);
                ++count;
            }
        }
        cout << count << endl;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
using ll = long long;
constexpr ll MOD = 1000000007;
constexpr ll INF = 1ll<<60;

ll field[60][60];
bool f[60][60];
ll W, H;

void dfs(ll h, ll w)
{
	if (f[h][w]) return;
	f[h][w] = true;
	for (ll i = -1; i <= 1; ++i)
		for (ll j = -1; j <= 1; ++j)
		{
			ll nw = w + i;
			ll nh = h + j;
			if (nw < 0 || nw > W || nh < 0 || nh > H) continue;
			if (field[nh][nw])
				dfs(nh, nw);
		}
}

int main(int argc, char **argv)
{
	while (cin >> W >> H, true)
	{
		if (W == 0 && H == 0) break;
		memset(f, 0, sizeof f);
		memset(field, 0, sizeof field);

		vector<pair<ll, ll>> search;
		search.reserve(50*50);
		for (ll h = 0; h < H; ++h)
			for (ll w = 0; w < W; ++w)
			{
				cin >> field[h][w];
				if (field[h][w] == 1)
				{
					search.push_back(pair<ll, ll>(h, w));
					// std::cout << "(h, w) : " << h << ", " << w << std::endl;
				}
			}
		
		ll res{0};
		for (ll i = 0; i < (ll)search.size(); ++i)
		{
			if (!f[search[i].first][search[i].second])
			{
				// std::cout << "(h, w) : " << search[i].first << ", " << search[i].second << std::endl;
				dfs(search[i].first, search[i].second);
				++res;
			}
		}
		std::cout << res << std::endl;

	}
}

C++: #include<bits/stdc++.h>
using namespace std;
#define rep(i, n) for (int i = 0; i < (int)(n); i++)

int dx[8]={1,0,-1,0,1,1,-1,-1};
int dy[8]={0,1,0,-1,1,-1,1,-1};
bool seen[50][50];
int G[50][50];

void dfs(int x,int y,int h,int w){
    seen[x][y]=true;

    rep(i,8){
        int nx=x+dx[i];
        int ny=y+dy[i];
        if(nx<0||nx>h-1||ny<0||ny>w-1)continue;
        if(seen[nx][ny])continue;
        if(G[nx][ny]==0)continue;
        dfs(nx,ny,h,w);
    }
}

int main(){
    while(1){
        int h,w;
        int ans=0;
        cin>>w>>h;
        if(w==0&&h==0)break;
        rep(i,h)rep(j,w)cin>>G[i][j];
        rep(i,50)rep(j,50)seen[i][j]=false;
        rep(i,h)rep(j,w){
            if(seen[i][j]==false&&G[i][j]==1){
                ans++;
                dfs(i,j,h,w);
            }
        }
        cout<<ans<<endl;
    }
    return 0;
}