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 <algorithm>
#include <iostream>
#include <string>
#include <cstring>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <deque>
#include <iomanip>
#include <limits>
#include <map>
#include <queue>
#include <stack>
#include <vector>

#define FOR(i,k,n) for(int (i) = (k); (i) < (n); ++(i))
#define rep(i,n) FOR(i,0,n)
#define pb push_back
#define all(v) begin(v), end(v)
#define debug(x) cerr << #x << ": " << x << endl
#define debug2(x,y) cerr << #x << ": " << x << ", " << #y << ": " << y << endl

using namespace std;
typedef long long ll;
typedef unsigned long long ull;
typedef pair<int, int> i_i;
typedef pair<i_i, int> p_i;
typedef vector<int> vi;
typedef vector< vector<int> > vvi;
template<class T> using vv=vector< vector<T> >;
typedef deque<int> di;
typedef deque< deque<int> > ddi;

int dx[3] = {-1,0,1}, dy[3] = {-1,0,1};

int c[55][55] = {};

void dfs(i_i p) {
    c[p.first][p.second] = 0;
    rep(i,3) {
        rep(j,3) {
            if(c[p.first+dx[i]][p.second+dy[j]] == 1) {
                dfs(make_pair(p.first+dx[i], p.second+dy[j]));
            }
        }
    }
}

int main() {
    int w,h;
    while(cin >> w >> h,w) {
        memset(c,0,sizeof(c));
        FOR(i,1,h+1) {
            FOR(j,1,w+1) {
                cin >> c[i][j];
            }
        }
        int sum = 0;
        FOR(i,1,h+1) {
            FOR(j,1,w+1) {
                if(c[i][j] == 1) {
                    dfs(make_pair(i,j));
                    sum += 1;
                }
            }
        }
        cout << sum << endl;
    }
	return 0;
}

C++: #include<bits/stdc++.h>
#define rep(i,a,b) for(int i=int(a);i<int(b);++i)
using namespace std;
typedef long long ll;
int INF = (1LL << 30) - 1;
int MOD = 1e9+7;
int H,W;
void dfs(int h,int w,vector<vector<int> > &table){
    //cout << h << " " << w << endl;
    table[h][w] = 0;
    int dx[] = {-1,-1,-1,0 ,0,1 ,1,1};
    int dy[] = {-1,0 ,1 ,-1,1,-1,0,1};
    rep(i,0,8){
        int nx = w + dx[i];
        int ny = h + dy[i];
        if (nx >= W || nx < 0 || ny >= H || ny < 0) continue;
        if(table[ny][nx])dfs(ny,nx,table);
    }
}
main(){
    cin >> W >> H;
    vector< vector<int> > table;
    while(W){
        table = vector< vector<int> > (H,vector<int>(W) );
        rep(i,0,H)rep(j,0,W)cin >> table[i][j];
        rep(i,0,H)rep(j,0,W)cout << table[i][j] << " \n"[j==W-1];
        int cnt = 0;
        rep(i,0,H)rep(j,0,W){
            if(table[i][j] == 1){
                //cout << i << " " << j << endl;
                dfs(i,j,table);
                cnt++;
            }
        }
        cout << cnt << endl;
        cin >> H >> W;
    }
}

C++: #include <cstdio>
#include <iostream>
 
using namespace std;
 
int main(void){
    
    while(1){
        
        int w, h;
        
        cin >> w >> h;
        if(w == 0 && h == 0) break;
        
        int map[52][52] = { {0} };
        int check[52][52] = { {0} };
        
        int i, j;
        for(j=1; j<=h; j++){
            for(i=1; i<=w; i++){
                cin >> map[j][i];
            }
        }
        
        
        int label = 1;
        
        int x, y;
        for(y=1; y<=h; y++){
            for(x=1; x<=w; x++){
                if(map[y][x] == 1){
                    if(check[y][x-1] || check[y-1][x-1] || check[y-1][x] || check[y-1][x+1]){
                        int min;
                        if(check[y][x-1]){
                            min = check[y][x-1];
                        } else {
                            min = 2500;
                        }
                        for(int k=x-1; k<=x+1; k++){
                            if(check[y-1][k] != 0 && check[y-1][k] < min) min = check[y-1][k];
                        }
                        check[y][x] = min;
                    } else {
                        check[y][x] = label;
                        label++;
                    }
                }
            }
        }
        
        
        for(y=h; y>0; y--){
            for(x=w; x>0; x--){
                if(check[y][x]){
                    int min = check[y][x];
                    for(int n=y-1; n<=y+1; n++){
                        for(int k=x-1; k<=x+1; k++){
                            if(check[n][k] != 0 && check[n][k] < min) min = check[n][k];
                        }
                    }
                    check[y][x] = min;
                }
            }
        }
        
        int count = 0;
        
        for(y=1; y<=h; y++){
            for(x=1; x<=w; x++){
                if(count < check[y][x]) count = check[y][x];
            }
        }
        
        cout << count << endl;
        
    }
    
    
    return 0;
}