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++: //AOJ How many islands?
#include<bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for(int i=a;i<n;i++)//repをdefineした際は=でつながないようにね
#define rep2(i,a,n) for(int i=a;i<=n;i++)
int H,W;
vector<vector<int>> area;

void dfs(int i,int j){
    area[i][j]=0; //0にしておくことで隣接したマス目の探索をしているときに再度探索されることを防ぐ
    rep2(di,-1,1) rep2(dj,-1,1) {
        int ni=i+di,nj=j+dj;
        if(ni<0||nj<0||ni>=H||nj>=W) continue;
        if(area[ni][nj]==0) continue;
       // cout<<ni<<" "<<nj<<endl;
        dfs(ni,nj);
    }    
    //帰りがけの処理をするならここで
    return;
}

int main() {

while(cin>>W>>H,H!=0&&W!=0){
    area.assign(H,vector<int>(W,0));//area 2次元配列の初期化はassignを使うとforを使った代入の必要がない 
    rep(i,0,H) rep(j,0,W) cin>>area[i][j]; 
    //探索開始
    int c=0;
    rep(i,0,H) rep(j,0,W) {
        if(area[i][j]==0) continue;
        dfs(i,j);
        c++;
    }
    cout<<c<<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] == 1)
			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) {
				++sum;
				dfs(j, i);
			}
		}
	}
	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)
				std::cin >> c[i][j];
		}
		int res = solve();
		std::cout << res << std::endl;
	}
	return 0;
}

C++: #include <stdio.h>
#include <algorithm>
#include <vector>
#include <queue>
#include <memory.h>
#include <functional>

using namespace std;

//FILE * in = freopen("B", "r", stdin);

typedef pair<int,int> P;

int n, m;
int cnt = 0;
int data[100][100];
int check[100][100];

int mvx[] = {-1, 0, 1, -1, 1, -1, 0, 1};
int mvy[] = {-1, -1, -1, 0, 0, 1, 1, 1};

void input() {
	for(int i = 0; i < m; i++){
		for(int j = 0; j < n; j++) {
			scanf("%d", &data[i][j]);
		}
	}
	cnt = 0;
	memset(check, 0, sizeof(check));
}

void bfs(int x, int y) {
	queue<P> que;
	que.push(P(x,y));
	check[x][y] = 1;
	while(!que.empty()){
		P cur = que.front(); que.pop();
		for(int i = 0; i < 8; i++) {
			if(cur.first + mvx[i] >= 0 && cur.first + mvx[i] < n && cur.second + mvy[i] >= 0 && cur.second + mvy[i] < m
				&& data[cur.first + mvx[i]][cur.second + mvy[i]] && !check[cur.first+mvx[i]][cur.second+mvy[i]]){
					check[cur.first +mvx[i]][cur.second+mvy[i]] = 1;
					que.push(P(cur.first+mvx[i], cur.second+mvy[i]));
			}
		}
	}
}

void process() {
	for(int i = 0; i < m; i++) {
		for(int j = 0; j < n; j++) {
			if(data[i][j] && !check[i][j]) {
				bfs(i,j);
				++cnt;
			}
		}
	}
	printf("%d\n", cnt);
}

int main() {
	while(true) {
		scanf("%d%d", &n, &m);
		if(n == 0) break;
		input();
		process();
	}
	return 0;
}

C++: #include <bits/stdc++.h> 

using namespace std;
using ll=long long;
using ull=unsigned long long;
using pii=pair<int,int>;

#define INF LONG_MAX
#define MOD 1000000007
#define rng(a) a.begin(),a.end()
#define rrng(a) a.end(),a.begin()

int main(){
  ios::sync_with_stdio(false);
  cin.tie(0);

  while(true){
    int W,H;
    cin>>W>>H;
    if(H==0&&W==0)break;
    vector<vector<int>>c(H,vector<int>(W));
    for(int i=0;i<H;i++)for(int j=0;j<W;j++)cin>>c[i][j];
    queue<pii>q;
    int dx[8]={0,0,1,-1,1,-1,-1,1};
    int dy[8]={1,-1,0,0,1,-1,1,-1};
    int ans=0;
    for(int i=0;i<H;i++){
      for(int j=0;j<W;j++){
        if(c[i][j]==0)continue;
        c[i][j]=0;
        q.push({i,j});
        while(q.size()){
          int y=q.front().first;
          int x=q.front().second;
          q.pop();
          for(int k=0;k<8;k++){
            int X=x+dx[k];
            int Y=y+dy[k];
            if(0<=X&&X<W&&0<=Y&&Y<H&&c[Y][X]==1){
              c[Y][X]=0;
              q.push({Y,X});
            }
          }
        }
        ans++;
      }
    }
    cout<<ans<<endl;
  }
  return 0;
}

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

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

int map[51][51];
int w, h;

void oneIsland(int x, int y) {
	map[y][x] = 0;
	for (int i = 0; i < 8; i++) {
		int nextX = x + dx[i];
		int nextY = y + dy[i];
		if (nextX < 0 || w <= nextX) continue;
		if (nextY < 0 || w <= nextY) continue;
		if (map[nextY][nextX] == 1) {
			oneIsland(nextX, nextY);
		}
	}
}

int main() {
	while (1) {
		cin >> w >> h;
		if (w == 0 && h == 0) break;
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				cin >> map[i][j];
			}
		}
		
		int count = 0;
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (map[i][j] == 1) {
					oneIsland(j, i);
					count++;
				}
			}
		}
		cout << count <<endl;
	}
}