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 <vector>
#include <algorithm>

typedef long long ll;
using namespace std;

int H, W;
vector<vector<int>> C;
vector<vector<int>> visited;
int ans = 0;





void dfs(int &i, int &j){
    visited[i][j] = 1;
    for(int y=-1; y<=1; y++){
        for(int x=-1; x<=1; x++){
            int ny = i+y;
            int nx = j+x;
            
            if(ny>=0 && ny<H && nx>=0 && nx<W && C[ny][nx] && !visited[ny][nx]) dfs(ny, nx);
        }
    }
    return;
}




int main() {
    while(1){
        ans = 0;
        visited.clear();
        
        cin >> W >> H; if((W&H)==0) break;
        C.resize(H);
        for(vector<int> &v:C) v.resize(W);
        for(vector<int> &row:C)
            for(int &c:row) cin >> c;

        visited.resize(H);
        for(vector<int> &v:visited) v.resize(W);

        for(int i=0; i<H; i++){
            for(int j=0; j<W; j++){
                if(C[i][j] && !visited[i][j]){
                    dfs(i,j);
                    ans ++;
                }
            }
        }
        
        
        cout << ans << endl;
    }
    return 0;
}

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

bool f[51][51];
int w, h;
int dx[8] = { 0, 0, -1,  1, -1,  1, -1,  1};
int dy[8] = {-1, 1,  0,  0, -1, -1,  1,  1};

void dfs(int x, int y) {
	if(!f[y][x]) return;
	f[y][x] = 0;
	for (int i = 0; i < 8; i++) {
		if (x + dx[i] < w && y + dy[i] < h
			 && x + dx[i] >= 0 && y + y + dy[i] >= 0)
			dfs(x + dx[i], y + dy[i]);
	}
}

int main()
{	
	int n;
	
	while (cin >> w >> h, w) {
		n = 0;
		
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				cin >> f[i][j];
			}
		}
		
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (f[i][j]) {
					n++;
					dfs(j, i);
				}
			}
		}
		
		cout << n << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for (ll i = 0; i < n; ++i)
#define sz(x) int(x.size())
#define ALL(c) (c).begin(), (c).end()
#define SUM(x) std::accumulate(ALL(x), 0LL)
#define MIN(v) *std::min_element(v.begin(), v.end())
#define MAX(v) *std::max_element(v.begin(), v.end())
#define EXIST(v, x) (std::find(v.begin(), v.end(), x) != v.end())
#define FORV(i, v) for (auto i = v.begin(); i != v.end(); i++)
using namespace std;

using ll = long long;

template<class T> inline bool chmax(T& a, T b) { if (a < b) { a = b; return true; } return false; }
template<class T> inline bool chmin(T& a, T b) { if (a > b) { a = b; return true; } return false; }
const int INF = 1001001001;
const long long INFLL = LLONG_MAX / 3;
const double eps = (1e-9);

int dh[] = {-1, -1, -1, 0, 0, 1, 1, 1};
int dw[] = {-1, 0, 1, -1, 1, -1, 0, 1};

void dfs(const vector<vector<int>>& c, vector<vector<bool>>& visited, int h, int w) {
  visited[h][w] = true;
  rep(i, 8) {
    int nh = h + dh[i];
    int nw = w + dw[i];
    if (nh < 0 || nh >= c.size() || nw < 0 || nw >= c[0].size()) continue;
    if (visited[nh][nw]) continue;
    if (c[nh][nw] == 0) continue;
    dfs(c, visited, nh, nw);
  }
}

bool solve() {
  int w, h; cin >> w >> h;
  if (w == 0 && h == 0) return false;
  vector<vector<int>> c(h, vector<int>(w));
  rep(i, h) rep(j, w) cin >> c[i][j];
  vector<vector<bool>> visited(h, vector<bool>(w, false));

  int ans = 0;
  rep(i, h) rep(j, w) {
    if (visited[i][j]) continue;
    if (c[i][j] == 0) continue;
    dfs(c, visited, i, j);
    ans++;
  }
  cout << ans << endl;
  return true;
}

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

  while (solve()) {}

  return 0;
}

C++: #include<iostream>
#include<string>
using namespace std;
int dp[50][50];
int main(){
	int w,h;
	while(true){
	cin>>w>>h;
	if(w==0&&h==0)
		break;
	for(int i=0;i<h;i++)
		for(int j=0;j<w;j++)
			cin>>dp[i][j];
	int count=0;
	while(true){
		bool t=true;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(dp[i][j]!=0)
					t=false;
			}
		}
		if(t==true)
			break;
		int x=0,y=0;
		while(true){
			x=0;
			while(true){
				if(dp[y][x]==1){
					t=true;
					break;
				}
				x++;
				if(x==w)
					break;
			}
			if(t==true)
				break;
			y++;
		}
		for(int f=max(0,y-1);f<=min(h-1,y+1);f++){
			for(int g=max(0,x-1);g<=min(w-1,x+1);g++){
				if(dp[f][g]==1)
				    dp[f][g]=2;
			}
		}
		dp[y][x]=0;
		while(true){
			t=true;
			for(int i=0;i<h;i++){
				for(int j=0;j<w;j++){
					if(dp[i][j]==2){
						for(int f=max(0,i-1);f<=min(h-1,i+1);f++){
			                for(int g=max(0,j-1);g<=min(w-1,j+1);g++){
								if(dp[f][g]==1)
				                    dp[f][g]=2;
			                }
						}
						dp[i][j]=0;
						t=false;
					}
				}
			}
			if(t==true)
				break;
		}
		count++;
	}
	cout<<count<<endl;
	}
	return 0;
}