Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"os"
	"strconv"
)

const (
	initialBufSize = 100000
	maxBufSize     = 1000000
)

var sc *bufio.Scanner

func initScanner(r io.Reader) *bufio.Scanner {
	buf := make([]byte, initialBufSize)

	sc := bufio.NewScanner(r)
	sc.Buffer(buf, maxBufSize)
	sc.Split(bufio.ScanWords) // bufio.ScanLines
	return sc
}

func main() {
	sc = initScanner(os.Stdin)
	resolve()
}

func resolve() {
	results := []int{}
	for true {
		w, h := scanInt(sc), scanInt(sc)
		if w == 0 && h == 0 {
			break
		}
		grid := make([][]int, h)
		for i := 0; i < h; i++ {
			grid[i] = make([]int, w)
			for j := 0; j < w; j++ {
				grid[i][j] = scanInt(sc)
			}
		}
		num := 0
		for i := range loop0(h) {
			for j := range loop0(w) {
				start := pos{y: i, x: j}
				if grid[start.y][start.x] == 0 {
					continue
				}
				num++
				_dfs(grid, w, h, start)
			}
		}
		results = append(results, num)
	}
	for _, v := range results {
		fmt.Println(v)
	}
	return
}

func _dfs(grid [][]int, w, h int, start pos) {
	grid[start.y][start.x] = 0
	for _, df := range []pos{
		pos{1, 0}, pos{-1, 0},
		pos{0, -1}, pos{0, 1},
		pos{1, 1}, pos{-1, -1},
		pos{-1, 1}, pos{1, -1},
	} {
		np := addPos(start, df)
		if np.y < 0 || h <= np.y || np.x < 0 || w <= np.x {
			continue
		}
		if grid[np.y][np.x] == 0 {
			continue
		}
		_dfs(grid, w, h, np)
	}
}

type pos struct{ x, y int }

func addPos(p, d pos) pos {
	return pos{
		x: p.x + d.x,
		y: p.y + d.y,
	}
}

func loop0(n int) chan int {
	return loop(0, n-1, 1)
}

func loop1(n int) chan int {
	return loop(1, n, 1)
}

func loop(s, e, d int) chan int {
	ch := make(chan int)
	go func() {
		for i := s; i <= e; i += d {
			ch <- i
		}
		close(ch)
	}()
	return ch
}

// snip-scan-funcs
func scanInt(sc *bufio.Scanner) int {
	sc.Scan()
	i, _ := strconv.Atoi(sc.Text())
	return int(i)
}
func scanString(sc *bufio.Scanner) string {
	sc.Scan()
	return sc.Text()
}

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

int W,H, grid[50][50];

int dfs(int sy, int sx){
	if(grid[sy][sx]==0)return 0;

	stack<pair<int,int>> S;
	S.push( {sy,sx} );

	while(S.size()){
		pair<int,int> u=S.top();	S.pop();
		grid[u.first][u.second]=0;

		for(int dy=-1; dy<=1; dy++){
			for(int dx=-1; dx<=1; dx++){
				int nY=u.first+dy, nX=u.second+dx;
				if(nY<0||nX<0||nY>=H||nX>=W)continue;
				else if(grid[nY][nX]==0)continue;

				S.push( {nY,nX} );
			}
		}
	}
	return 1;
}

int main(){
	while((cin>>W>>H)&&W&&H){
		for(int i=0;i<H;i++){
			for(int j=0;j<W;j++){
				cin>>grid[i][j];
			}
		}

		int ans=0;
		for(int i=0;i<H;i++){
			for(int j=0;j<W;j++){
				ans+=dfs(i,j);
			}
		}
		cout<<ans<<endl;
	}

	return 0;
}

C++: #include "bits/stdc++.h"

#define REP(i,n) for(int i=0;i<n;++i)
#define RREP(i,n) for(int i=n-1;i>=0;--i)
#define FOR(i,m,n) for(int i=m;i<n;++i)
#define RFOR(i,m,n) for(int i=m-1;i>=n;--i)
#define ALL(v) v.begin(),v.end()
#define PB(a) push_back(a)
#define INF 1000000001
#define MOD 1000000007

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

using namespace std;

void dfs(vector<vector<int> > &v,int x,int y) {
	v[x][y] = 0;
	REP(i, 8) {
		int nx = x + dx[i], ny = y+dy[i];
		if (nx >= 0 && ny >= 0 && nx < v.size() && ny < v[0].size() && v[nx][ny] == 1) {

			dfs(v, nx, ny);
		}
	}
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	while (1) {
		int w, h, cnt = 0;
		cin >> w >> h;
		if (!w) break;
		vector<int> dm(w);
		vector<vector<int> > v(h, dm);
		REP(i, h)REP(j, w) cin >> v[i][j];
		REP(i, h)REP(j, w)
			if (v[i][j] == 1) {
				dfs(v, i, j);
				cnt++;
			}
		cout << cnt << endl;
	}
	return 0;
}

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

using namespace std;
typedef long long ll;

#define LOOP(i, a, n) for (int i = (int)a; i < (int)n; ++i)
#define REP(i, n) LOOP(i, 0, n)
#define MOD 1000000007
#define INF 1000000000
#define PI 3.14159265359
#define MAX_W 50
#define MAX_H 50

int dx[8] = {0, 0, -1, 1, 1, 1, -1, -1}, dy[8] = {-1, 1, 0, 0, -1, 1, -1, 1}, board[MAX_H][MAX_W], w, h;

void dfs(int x, int y) {
  board[y][x] = 0;

  for (int i = 0; i < 8; i++) {
    int nextx = x + dx[i], nexty = y + dy[i];
    if (nextx >= 0 && nextx < w && nexty >= 0 && nexty < h && board[nexty][nextx] == 1) {
      dfs(nextx, nexty);
    }
  }

  return;
}

int main(void) {
  vector<int> ans;

  while (true) {
    cin >> w >> h;
    if (w == 0 && h == 0) {
      break;
    }
    fill(board[0], board[49], 0);
    for (int i = 0; i < h; i++) {
      for (int j = 0; j < w; j++) {
        cin >> board[i][j];
        //cout << "i:" << i << " j:" << j << endl;
      }
    }

    int res = 0;
    for (int i = 0; i < h; i++) {
      for (int j = 0; j < w; j++) {
        if (board[i][j] == 1) {
          dfs(j, i);
          res++;
        }
      }
    }

    ans.push_back(res);
  }

  for (int i = 0; i < ans.size(); i++) {
    cout << ans[i] << endl;
  }
  return 0;
}