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 <bits/stdc++.h>
#define rep(i,n) for (int i = (0); i < (n); ++i)
#define rrep(i,n) for(int i = 1; i <= (n); ++i)
#define drep(i,n) for(int i = (n)-1; i >= 0; --i)
#define srep(i,s,t) for (int i = s; i < t; ++i)
#define all(x) (x).begin(),(x).end()
#define rall(x) (x).rbegin(),(x).rend()
#define limit(x,l,r) max(l,min(x,r))
#define lims(x,l,r) (x = max(l,min(x,r)))
#define isin(x,l,r) ((l) <= (x) && (x) < (r))
#define show(x) cout << #x << " = " << (x) << endl
#define show2(x,y) cout << #x << " = " << (x) << ", " << #y << " = " << (y) << endl
#define show3(x,y,z) cout << #x << " = " << (x) << ", " << #y << " = " << (y) <<  ", " << #z << " = " << (z) << endl
#define showv(v) rep(i,v.size()) printf("%d%c", v[i], i==v.size()-1?'\n':' ')
#define showv2(v) rep(j,v.size()) showv(v[j])
#define showt(t,n) rep(i,n) printf("%d%c", t[i], i==n-1?'\n':' ')
#define showt2(t,r,c) rep(j,r) showt(t[j],c)
#define showvp(p) rep(i,p.size()) printf("%d %d\n", p[i].first, p[i].second)
#define printv(v) rep(i,v.size()) printf("%d\n", v[i])
#define printt(t,n) rep(i,n) printf("%d\n", t[i])
#define incl(v,x) (find(all(v),x)!=v.end())
#define incls(s,c) (s.find(c)!=string::npos)
#define lb(a,x) distance((a).begin(),lower_bound(all(a),(x)))
#define ub(a,x) distance((a).begin(),upper_bound(all(a),(x)))
#define fi first
#define se second
#define pb push_back
#define eb emplace_back
#define sz(x) (int)(x).size()
#define pcnt __builtin_popcountll
#define bit(n,k) ((n>>k)&1) // nのk bit目
#define bn(x) ((1<<x)-1)
#define dup(x,y) (((x)+(y)-1)/(y))
#define newline puts("")
#define uni(x) x.erase(unique(all(x)),x.end())
#define SP << " " <<
#define v(T) vector<T>
#define vv(T) v(v(T))
using namespace std;
using ll = long long;
using ld = long double;
using vi = vector<int>;
using vvi = vector<vi>;
using vl = vector<ll>;
using vvl = vector<vl>;
using vs = vector<string>;
using P = pair<int, int>;
using T = tuple<int, int, int>;
using vp = vector<P>;
using vt = vector<T>;
const int mod = 1000000007;
const double EPS = 1e-9;
//const long double EPS = 1e-14;
const int INF = (1<<30)-1;
const ll LINF = (1LL<<62)-1;
#define dame { puts("No"); return 0;}
#define yn {puts("Yes");}else{puts("No");}
inline int in() { int x; cin >> x; return x;}
inline ll lin() { ll x; cin >> x; return x;}
inline char chin() { char x; cin >> x; return x;}
inline string stin() { string x; cin >> x; return x;}
inline double din() { double x; cin >> x; return x;}
//template<class T = int> inline T in() { T x; cin >> x; return (x);}
template<typename T>inline ll suma(const v(T)& a) { ll res(0); for (auto&& x : a) res += x; return res;}
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; }
char itoa(int n) { return n + '0';}
ll gcd(ll a, ll b) { return b?gcd(b,a%b):a;}
ll lcm(ll a, ll b) { return a/gcd(a,b)*b;}
const int dx[8] = {1, 1, 0, -1, -1, -1,  0,  1};
const int dy[8] = {0, 1, 1,  1,  0, -1, -1, -1};

int w, h;
int c[55][55];

void dfs(int y, int x) {
  c[y][x] = 0;
  rep(i,8) {
    int ny = y + dy[i];
    int nx = x + dx[i];
    if (!isin(ny,0,h) || !isin(nx,0,w)) continue;
    if (c[ny][nx]) dfs(ny,nx);
  }
  return;
}

int main () {
  while (true) {
    cin >> w >> h;
    if (w == 0 && h == 0) break;
    rep(i,h)rep(j,w) cin >> c[i][j];
    int ans = 0;
    rep(i,h)rep(j,w) {
      if (c[i][j]) {
        ans++;
        dfs(i,j);
      }
    }
    printf("%d\n", ans);
  }
  return 0;
}

C++: #include<iostream>
using namespace std;
void b(int ,int );
int a[100][100]={};
 
int main(){
  while(1){
    int count=0,w,h;
    cin>>w>>h;
    if(w+h==0)break;
     
    for(int i=1;i<=h;i++)
      for(int j=1;j<=w;j++)
    cin>>a[i][j];
 
    for(int i=1;i<=h;i++)
      for(int j=1;j<=w;j++)
    if(a[i][j]==1){
      dfs(j,i);
      count++;
    }
    cout<<count<<endl;  
  }
  return 0;
}
 
  void b(int x,int y){
    a[y][x]=0;
    int x1,y1;
    int x2[8]={-1,0,1,1,1,0,-1,-1};
    int y2[8]={1,1,1,0,-1,-1,-1,0};
    for(int k=0;k<8;k++){
    x1=x+x2[k];
    y1=y+y2[k];
    if(a[y1][x1]==1)
      dfs(x1,y1);
    }
  }

C++: #include <iostream>
#include <algorithm>
#include <vector>
#define rep(i,n) for(int i=0;i<n;++i)
#define rep1(i,n) for(int i=1;i<=n;++i)
using namespace std;
class Grid{
private:
  int h,w;
  vector<vector<int>> c;
  vector<int> dx={1,0,-1,1,-1,1,0,-1};
  vector<int> dy={1,1,1,0,0,-1,-1,-1};
public:
  //***************Constractor****************************
  Grid(int _h,int _w,vector<vector<int>> _c){
    w = _w;h = _h;c = _c;
  }

  //***********************************************
  
  void simple_dfs(int x,int y){
    c[x][y] = 0;
    rep(i,8){
      int nx = x + dx[i],ny = y + dy[i];
      if(nx>=0&&nx<h&&ny>=0&&ny<w) if(c[nx][ny]==1) simple_dfs(nx,ny);
    }
  }

  int run_dfs(){//check each node can reach goal
    int res=0;
    rep(x,h) rep(y,w){
      if(c[x][y]==1){
	res++ ;
	simple_dfs(x,y);
      }
    }
    return res;
  }

  void show(){
    rep(i,h){
      rep(j,w) cout << c[i][j] << " ";
      cout  << "\n";
    }
  }
  
};


int main()
{
  int w,h;
  vector<int> res;
  while(1){
    cin >> w >> h;
    if(w==0&&h==0) break;
    vector<vector<int>> c(h,vector<int>(w));
    rep(i,h) rep(j,w) cin >> c[i][j];
    Grid gr(h,w,c);
    res.push_back(gr.run_dfs());
  }
  rep(i,res.size()) cout << res[i] << "\n";
  return 0;
}