Go: ///
// File:  1160.go
// Author: ymiyamoto
//
// Created on Sun Mar  4 20:45:57 2018
//
package main

import (
	"fmt"
)

var w, h int
var graph [][]string

func dfs(visited [][]bool, x, y int) {
	visited[x][y] = true

	for i := -1; i <= 1; i++ {
		for j := -1; j <= 1; j++ {
			dx := x + i
			dy := y + j
			if 0 <= dx && dx < h && 0 <= dy && dy < w && graph[dx][dy] == "1" && !visited[dx][dy] {
				dfs(visited, dx, dy)
			}
		}
	}
}

func main() {
	for {
		fmt.Scan(&w, &h)
		if w == 0 && h == 0 {
			break
		}

		graph = make([][]string, h)
		for i := range graph {
			graph[i] = make([]string, w)
		}

		for i := 0; i < h; i++ {
			for j := 0; j < w; j++ {
				var s string
				fmt.Scan(&s)
				graph[i][j] = s
			}
		}

		visited := make([][]bool, h)
		for i := range visited {
			visited[i] = make([]bool, w)
		}

		count := 0
		for i := range graph {
			for j := range graph[i] {
				if graph[i][j] == "1" && !visited[i][j] {
					dfs(visited, i, j)
					count++
				}
			}
		}

		fmt.Println(count)
	}
}

C++: #include <algorithm>
#include <bitset>
#include <climits>
#include <complex>
#include <deque>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <limits>
#include <list>
#include <map>
#include <memory>
#include <new>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <streambuf>
#include <string>
#include <tuple>
#include <utility>
#include <valarray>
#include <vector>

#define rep(i, a, n) for(int i = (a);i < (n);i++)
#define REP(i, n)    rep(i, 0, n)
#define all(e)       (e).begin(), (e).end()

#ifdef LOCAL
#define show(x) cerr<<__LINE__<<" : "<<#x<<" = "<<(x)<<endl;
#else
#define show() true
#endif

using namespace std;
using ll=long long;
template<class T> using V=vector<T>;

template<class T, class U>
void chmin(T &t, const U u) { if (t > u) t = u; }

template<class T, class U>
void chmax(T &t, const U u) { if (t < u) t = u; }

const int INF = (1 << 30) - 1;
const ll INFL = (ll) 5e15;
const int MOD = 1000000007;

using P=pair<int, int>;

class Solver {
public:
    bool solve() {
        cin >> W >> H;
        if (W == 0 && H == 0) return false;

        field.resize(W, V<int>(H));
        REP(y, H) {
            REP(x, W) {
                cin >> field[x][y];
            }
        }

        int c = 2;
        REP(y, H) {
            REP(x, W) {
                if (field[x][y] == 1) {
                    bfs(P(x, y), c);
                    ans++;
                }
            }
        }

        cout << ans << endl;
        return true;
    }

private:
    int H, W;
    V<V<int>> field;
    int ans = 0;

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

    void bfs(P s, int c) {
        queue<P> que;
        que.push(s);
        field[s.first][s.second] = c;
        while (que.size()) {
            P cur = que.front();
            que.pop();

            for (int i = 0; i < 8; ++i) {
                P next = {cur.first + dx[i], cur.second + dy[i]};
                if (check(next) && field[next.first][next.second] == 1) {
                    que.push(next);
                    field[next.first][next.second] = c;
                }
            }
        }
    }

    bool check(P p) {
        if (p.first < 0 || p.first >= W) return false;
        if (p.second < 0 || p.second >= H) return false;
        return true;
    }
};

int main() {

    while (Solver().solve());

    return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
bool d[51][51];
int a,b,s,_x,_y,dx[8]={0,-1,-1,-1,0,1,1,1},dy[8]={1,1,0,-1,-1,-1,0,1};
#define r(z,x) for(int z=0;z<x;z++)
void dfs(int x,int y){
	if(0>x||x>=b||0>y||y>=a)return;
	d[x][y]=0;
	r(i,8)if(d[_x=x+dx[i]][_y=y+dy[i]])dfs(_x,_y);
}
int main(){
	while(cin>>a>>b,a||b){
		s=0;
		r(i,b)r(j,a)cin>>d[i][j];
		r(i,b)r(j,a)if(d[i][j])dfs(i,j),s++;
		cout<<s<<endl;
	}
}

C++: #include <iostream>
#include <string.h>

using namespace std;
char field[52][52];
int dx[8] = {-1, -1, -1,  0, 0,  1, 1, 1};
int dy[8] = {-1,  0,  1, -1, 1, -1, 0, 1};

void DFS(int y, int x)
{
	field[y][x] = '0';
	for(int i = 0; i < 8; ++i)
	{
		int nx = x + dx[i];
		int ny = y + dy[i];
		if(field[ny][nx] == '1')
		{
			DFS(ny, nx);
		}
	}
}

void solve()
{
	int w, h;
	while(cin >> w >> h, w || h)
	{
		memset(field, 0, sizeof(field));
		for(int i = 1; i <= h; ++i)
		{
			for(int j = 1; j <= w; ++j)
			{
				cin >> field[i][j];
			}
		}
		int count = 0;
		for(int i = 1; i <= h; ++i)
		{
			for(int j = 1; j <= w; ++j)
			{
				if(field[i][j] == '1')
				{
					++count;
					DFS(i, j);
				}
			}
		}
		cout << count << endl;
	}
}

int main()
{
	solve();
	return(0);
}

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

int myMap[51][51];
int w, h;
int ans;

bool safe(int x, int y){
    return (0 <= x && 0 <= y) && (x < h && y < w);
}

void del(int x, int y){
    myMap[x][y] = 0;
    if (safe(x+1, y) && myMap[x+1][y]) del(x+1, y);
    if (safe(x+1, y+1) && myMap[x+1][y+1]) del(x+1, y+1);
    if (safe(x+1, y-1) && myMap[x+1][y-1]) del(x+1, y-1);
    if (safe(x, y+1) && myMap[x][y+1]) del(x, y+1);
    if (safe(x, y-1) && myMap[x][y-1]) del(x, y-1);
    if (safe(x-1, y-1) && myMap[x-1][y-1]) del(x-1, y-1);
    if (safe(x-1, y+1) && myMap[x-1][y+1]) del(x-1, y+1);
    if (safe(x-1, y) && myMap[x-1][y]) del(x-1, y);
    return;
}

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 >> myMap[i][j];
	    }
	}

	ans = 0;	
	for (int i = 0; i < w; i++){
	    for (int j = 0; j < h; j++){
		if (myMap[i][j] == 1){
		    cout << i << " " << j << endl;
		    ans++;
		    del(i, j);
		}
	    }
	}

	cout << ans << endl;
    }
}

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

int n, m;
int field[51][51];

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

void dfs(int y, int x){
    field[y][x] = 0;
    rep(i,8){
        int ny = y + dy[i];
        int nx = x + dx[i];
        if(ny < 0 || n < ny || nx < 0 || m < nx) continue;
        if(field[ny][nx] == 0) continue;
        dfs(ny, nx);
    }
}

int main(){
    cin.tie(0);
    ios::sync_with_stdio(false);
    while(1){
        cin >> m >> n;
        if(m == 0 && n == 0) break;
        rep(i,n)rep(j,m) cin >> field[i][j];
        int ans = 0;
        rep(i,n)rep(j,m){
            if(field[i][j] == 0) continue;
            dfs(i, j);
            ans++;
        }
        cout << ans << endl;
    }
    return 0;
}

C++: #define _GLIBCXX_DEBUG
#define rep(i, n) for (int i = 0; i < (int)(n); i++)
#define ALL(v) v.begin(), v.end()
typedef long long ll;

template<class T>bool chmax(T &a, const T &b) { if (a<b) { a=b; return 1; } return 0; }
template<class T>bool chmin(T &a, const T &b) { if (b<a) { a=b; return 1; } return 0; }

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

int C[55][55]={0};
int W,H;

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

void dfs(int h,int w){
  C[h][w]=0;
  
  rep(i,8){
    int nh=h+dy[i];
    int nw=w+dx[i];
    
    if(nh<0 || nh>=H || nw<0 || nw>=W) continue;
    if(C[nh][nw]==0) continue;
    
    dfs(nh,nw);
  }
}

int main(){
  
  while(cin>>W>>H){
    if(W==0 && H==0) return 0;
    
    int cnt=0;
    rep(i,H){
      rep(j,W) cin>>C[i][j];
    }
    
    rep(i,H){
      rep(j,W){
        if(C[i][j]==0) continue;
        dfs(i,j);
        cnt++;
      }
    }
    
    cout<<cnt<<endl;
  }
  
  return 0;
}