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++: // https://ei1333.github.io/luzhiled/
// http://beet-aizu.hatenablog.com/entry/2017/01/04/113233
// http://www.prefield.com/algorithm/
#include <bits/stdc++.h>
using namespace std;
using ll = long long;
using ld = long double;
using vl = vector<ll>;
using vd = vector<ld>;
using vs = vector<string>;
using vb = vector<bool>;
using vvl = vector<vector<ll>>;
using vvd = vector<vector<ld>>;
using vvs = vector<vector<string>>;
using vvb = vector<vector<bool>>;
#define pb push_back
#define eb emplace_back
#define fi first
#define se second
template<class T> using vc = vector<T>;
template<class T> using vvc = vector<vector<T>>;
using Graph = vector<vector<ll>>;
const ll INF = 1LL << 60;
void init() {cin.tie(0);ios::sync_with_stdio(false);cout << fixed << setprecision(15);}
const ll tl= 1'000'000'007;
#define REP(i, n) for (ll i = 0; i < n; i++)
#define REREP(i, n) for (ll i = n; i >= 0; i--)
#define FOR(i, a, n) for (ll i = a; i < n; i++)
#define REFOR(i, n, a) for (ll i = n; i >= a; i--)
#define UNIQUE(v) v.erase( unique(v.begin(), v.end()), v.end() ) //被り削除
#define debug cout << "line : " << __LINE__ << " debug" << endl;
#define ini(...) int __VA_ARGS__; in(__VA_ARGS__)
#define inl(...) long long __VA_ARGS__; in(__VA_ARGS__)
#define ind(...) long double __VA_ARGS__; in(__VA_ARGS__)
#define ins(...) string __VA_ARGS__; in(__VA_ARGS__)
#define inc(...) char __VA_ARGS__; in(__VA_ARGS__)
void in(){} template <typename T,class... U> void in(T &t,U &...u){ cin >> t; in(u...);}
void out(){cout << endl;} template <typename T,class... U> void out(const T &t,const U &...u){ cout << t; if(sizeof...(u)) cout << " "; out(u...);}
template<typename T>void die(T x){out(x); exit(0);}
#define in1(A) REP(i,A.size()) in(A[i]);
#define in2(A,B) REP(i,A.size()) in(A[i],B[i]);
#define in3(s,t,u) REP(i,sz(s)){in(s[i] , t[i] , u[i]);}
#define in4(s,t,u,v) REP(i,sz(s)){in(s[i] , t[i] , u[i] , v[i]);}
#define each(x,v) for(auto& x : v)
#define all(v) (v).begin(),(v).end()
#define sz(v) ((int)(v).size())
struct Point{ ld x,y; };
ld dist(Point a, Point b){return sqrt(abs(a.x-b.x)*abs(a.x-b.x)+abs(a.y-b.y)*abs(a.y-b.y));} // ２点間の距離 
ll gcd(ll a, ll b) { return b != 0 ? gcd(b, a % b) : a; }
ll lcm(ll a,ll b){ return a / gcd(a,b) * b;} 
ll fact(ll n){ if(n < 2) return 1; return (n * fact(n-1))%tl; } //階乗
inline ll updiv(ll a,ll b){ return (a + b - 1) / b; } //切り上げ
template<typename T,typename U>ll ceil(T a,U b){return (a + b - 1) / b;}
template <class A, class B> inline bool chmax(A &a, const B &b) { return b > a && (a = b, true); }
template <class A, class B> inline bool chmin(A &a, const B &b) { return b < a && (a = b, true); }
//-------------------------------------------------------------------------------------------------
struct grid{
    ll t,y;
};
int main(){
    init();
    while(1){
        ll ans=0;
        inl(w,h);
        if(h==0&&w==0) break;
        vvl A(h,vl(w,0));
        vvl visited(h,vl(w,0));
        REP(i,h){
            REP(j,w){
                cin >> A[i][j];
            }
        } 
        //grid上での深さ優先探索
        REP(i,h){
            REP(j,w){
                vector<grid> memo;
                if(A[i][j]==1 && visited[i][j]==0){
                    memo.pb({i,j});
                    ans++;
                
                    while(!memo.empty()){
                        grid p= memo.back();
                        memo.pop_back();
                        visited[p.t][p.y]=1;
                        // 縦横
                        REP(j,4){
                            // 1 3 5 7
                            ll ii= p.t+(2*j+1)/3-1;
                            ll jj= p.y+(2*j+1)%3-1;
                            // debug
                            if(0<=jj&&jj<w && 0<=ii&&ii<h){
                                if(A[ii][jj]==1 && visited[ii][jj]==0){
                                    memo.pb({ii,jj});
                                }
                            }
                        }
                        //斜め
                        REP(j,5){
                            if(j==2) continue;
                            // 0 2 6 8
                            // 4
                            ll ii= p.t+(2*j)/3-1;
                            ll jj= p.y+(2*j)%3-1;
                            // debug
                            if(0<=jj&&jj<w && 0<=ii&&ii<h){
                                if(A[ii][jj]==1 && visited[ii][jj]==0){
                                    memo.pb({ii,jj});
                                }
                            }
                        }
                    }
                }
            }
        }

        out(ans);
    }
    
}

C++: #include <bits/stdc++.h>
using namespace std;
template <class T>
inline bool chmax(T &a, T b)
{
    if (a < b)
    {
        a = b;
        return 1;
    }
    return 0;
}
template <class T>
inline bool chmin(T &a, T b)
{
    if (a > b)
    {
        a = b;
        return 1;
    }
    return 0;
}
typedef long long int ll;

#define ALL(v) (v).begin(), (v).end()
#define RALL(v) (v).rbegin(), (v).rend()
const double EPS = 1e-7;
const int INF = INT_MAX;
const ll LLINF = INT64_MAX;
const double PI = acos(-1);
const int MOD = 1000000007;

//-------------------------------------

using P = pair<int, int>;

void dfs(int x, int y, int h, int w, vector<vector<int>> &g, vector<vector<bool>> &seen)
{
    stack<P> st;
    st.push(P(x, y));
    while (st.size())
    {
        P now = st.top();
        st.pop();
        seen[now.second][now.first] = true;
        for (int dx = -1; dx <= 1; dx++)
        {
            for (int dy = -1; dy <= 1; dy++)
            {
                int nx = now.first + dx;
                int ny = now.second + dy;
                if (0 <= nx && nx < w && 0 <= ny && ny < h && !seen[ny][nx] && g[ny][nx] == 1)
                {
                    st.push(P(nx, ny));
                }
            }
        }
    }
}

int main()
{
    cin.tie(0);
    ios::sync_with_stdio(false);
    while (true)
    {
        int w, h;
        cin >> w >> h;
        if (w == 0 && h == 0)
        {
            return 0;
        }
        // 陸は1、海は0
        vector<vector<int>> g(h, vector<int>(w));
        for (int i = 0; i < h; i++)
        {
            for (int j = 0; j < w; j++)
            {
                cin >> g[i][j];
            }
        }
        vector<vector<bool>> seen(h, vector<bool>(w, false));
        int ans = 0;
        for (int y = 0; y < h; y++)
        {
            for (int x = 0; x < w; x++)
            {
                if (!seen[y][x] && g[y][x] == 1)
                {
                    dfs(x, y, h, w, g, seen);
                    ans++;
                }
            }
        }
        cout << ans << endl;
    }
}