Go: // AOJ 1160: How Many Islands? http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160

package main

import (
	"bufio"
	"container/list"
	"fmt"
	"os"
	"strconv"
)

var SEA = 0
var LAND = 1

func nextInt(sc *bufio.Scanner) int {
	sc.Scan()
	v, _ := strconv.Atoi(sc.Text())
	return v
}

func discoverIslands(M, V [][]int, H, W int) int {
	// 島を探す
	queue := list.New()
	islands := 0
	for i := 1; i <= H; i++ {
		for j := 1; j <= W; j++ {
			// 訪問済みの土地ならスキップ
			if V[i][j] == 1 {
				continue
			}

			// 訪問中の土地が海なら訪問済みにしてスキップ
			if M[i][j] == SEA {
				V[i][j] = 1
				continue
			}

			// 未訪問の陸地が見つかったので
			// 島の数を1つ増やし、この陸地から辿れる陸地を訪問していく
			islands++
			queue.PushBack([]int{i, j})

			for queue.Len() > 0 {
				cur := queue.Remove(queue.Front()).([]int)
				h, w := cur[0], cur[1]
				if V[h][w] == 1 {
					continue
				}
				V[h][w] = 1

				// 全方向に未訪問の陸地がないか探索
				for v := -1; v <= 1; v++ {
					for l := -1; l <= 1; l++ {
						dh := h + v
						dw := w + l
						if M[dh][dw] == LAND && V[dh][dw] == 0 {
							queue.PushBack([]int{dh, dw})
						}
					}
				}
				/*
					if M[h-1][w] == LAND {
						queue.PushBack([]int{h - 1, w})
					}
					if M[h-1][w+1] == LAND {
						queue.PushBack([]int{h - 1, w + 1})
					}
					if M[h][w+1] == LAND {
						queue.PushBack([]int{h, w + 1})
					}
					if M[h+1][w+1] == LAND {
						queue.PushBack([]int{h + 1, w + 1})
					}
					if M[h+1][w] == LAND {
						queue.PushBack([]int{h + 1, w})
					}
					if M[h+1][w-1] == LAND {
						queue.PushBack([]int{h + 1, w - 1})
					}
					if M[h][w-1] == LAND {
						queue.PushBack([]int{h, w - 1})
					}
					if M[h-1][w-1] == LAND {
						queue.PushBack([]int{h - 1, w - 1})
					}
				*/
			}
		}
	}
	return islands
}

func main() {
	sc := bufio.NewScanner(os.Stdin)
	sc.Split(bufio.ScanWords)

	for {
		W, H := nextInt(sc), nextInt(sc)

		if W == 0 && H == 0 {
			break
		}
		// Initialize map and visted list
		M := make([][]int, H+2)
		V := make([][]int, H+2)
		for i := 0; i < H+2; i++ {
			M[i] = make([]int, W+2)
			V[i] = make([]int, W+2)
		}
		for i := 1; i <= H; i++ {
			for j := 1; j <= W; j++ {
				M[i][j] = nextInt(sc)
			}
		}

		islands := discoverIslands(M, V, H, W)

		fmt.Println(islands)
	}
}

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

//#define int long long
typedef long long ll;

typedef unsigned long long ul;
typedef unsigned int ui;
const ll mod = 1000000007;
const ll INF = mod * mod;
const int INF_N = 1e+9;
typedef pair<int, int> P;
#define stop char nyaa;cin>>nyaa;
#define rep(i,n) for(int i=0;i<n;i++)
#define per(i,n) for(int i=n-1;i>=0;i--)
#define Rep(i,sta,n) for(int i=sta;i<n;i++)
#define rep1(i,n) for(int i=1;i<=n;i++)
#define per1(i,n) for(int i=n;i>=1;i--)
#define Rep1(i,sta,n) for(int i=sta;i<=n;i++)
#define all(v) (v).begin(),(v).end()
typedef pair<ll, ll> LP;
typedef long double ld;
typedef pair<ld, ld> LDP;
const ld eps = 1e-12;
const ld pi = acos(-1.0);
//typedef vector<vector<ll>> mat;
typedef vector<int> vec;

//繰り返し二乗法
ll mod_pow(ll a, ll n, ll m) {
	ll res = 1;
	while (n) {
		if (n & 1)res = res * a%m;
		a = a * a%m; n >>= 1;
	}
	return res;
}

struct modint {
	ll n;
	modint() :n(0) { ; }
	modint(ll m) :n(m) {
		if (n >= mod)n %= mod;
		else if (n < 0)n = (n%mod + mod) % mod;
	}
	operator int() { return n; }
};
bool operator==(modint a, modint b) { return a.n == b.n; }
modint operator+=(modint &a, modint b) { a.n += b.n; if (a.n >= mod)a.n -= mod; return a; }
modint operator-=(modint &a, modint b) { a.n -= b.n; if (a.n < 0)a.n += mod; return a; }
modint operator*=(modint &a, modint b) { a.n = ((ll)a.n*b.n) % mod; return a; }
modint operator+(modint a, modint b) { return a += b; }
modint operator-(modint a, modint b) { return a -= b; }
modint operator*(modint a, modint b) { return a *= b; }
modint operator^(modint a, int n) {
	if (n == 0)return modint(1);
	modint res = (a*a) ^ (n / 2);
	if (n % 2)res = res * a;
	return res;
}

//逆元(Eucledean algorithm)
ll inv(ll a, ll p) {
	return (a == 1 ? 1 : (1 - p * inv(p%a, a)) / a + p);
}
modint operator/(modint a, modint b) { return a * modint(inv(b, mod)); }

const int max_n = 1 << 18;
modint fact[max_n], factinv[max_n];
void init_f() {
	fact[0] = modint(1);
	for (int i = 0; i < max_n - 1; i++) {
		fact[i + 1] = fact[i] * modint(i + 1);
	}
	factinv[max_n - 1] = modint(1) / fact[max_n - 1];
	for (int i = max_n - 2; i >= 0; i--) {
		factinv[i] = factinv[i + 1] * modint(i + 1);
	}
}
modint comb(int a, int b) {
	if (a < 0 || b < 0 || a < b)return 0;
	return fact[a] * factinv[b] * factinv[a - b];
}
// using mP = pair<modint, modint>;

int dx[4] = { 0,1,0,-1 };
int dy[4] = { 1,0,-1,0 };


int H, W;
vector<vec> v;
void dfs(int h, int w){
	if(v[h][w] == 0) return;
	v[h][w] = 0;

	Rep1(i, -1, 1){
		Rep1(j, -1, 1){
			if(h+i < 0 || h+i > H-1 || w+j < 0 || w+j > W-1) continue;
			dfs(h+i, w+j);
		}
	}
}

void solve() {
    while(true){
        cin >> W >> H;
        if(H == 0 && W == 0)break;

		vector<vec> tmp(H, vec(W));
		rep(i, H){
			rep(j, W){
				int a; cin >> a;
				tmp[i][j] = a;
			}
		}
		v = tmp;

		int res = 0;
		rep(i, H){
			rep(j, W){
				if(v[i][j] == 1){
					dfs(i, j);
					res++;
				}
			}
		}
		cout << res << endl;
	}
}

signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  //cout << fixed << setprecision(10);
  //init_f();
  //init();
  //int t; cin >> t; rep(i, t)solve();
  solve();
//   stop
    return 0;
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <cmath>
#include <iomanip>
#include <stack>
#include <algorithm>
#include <iostream>
#include <string>
#include <map>
#include <queue>
#include <stdio.h>
#include <math.h>


using namespace std;

typedef long long ll;

typedef vector<vector<int>> vvi;
typedef vector<int> vi;
typedef vector<string> vs;
typedef vector<vector<string>> vvs;
typedef vector<ll> vll;

typedef pair<int, int> pii;

typedef queue<int> qi;
typedef queue<string> qs;


#define rep(i, n) for(int i=0; i<(n); ++i)
#define repp(i, a, b) for(int i = (a); i <= (b); i++)
#define Rep(i, n) for(int i=n; i >= 0; i--)

#define all(v) v.begin(), v.end()
//sort( all(v) )　などと使える

using field = vector<vector<int>>;

field c;

int w, h;

void dfs(field &c, int x, int y) {

	c[x][y] = 0;
	

	for (int dx = -1; dx <= 1; dx++) for (int dy = -1; dy <= 1; dy++) {
		int nx = x + dx, ny = y + dy;

		if (nx == x && ny == y) continue;

		else if (nx >= 0 && nx < h && ny >= 0 && ny < w && c[nx][ny] == 1) dfs(c, nx, ny);

	}
}


int main(void){
	

	while (cin >>w >> h) {		

		if (w == 0 && h == 0) break;

		c.assign(h, vector<int>(w));

		rep(i, h) rep(j, w) cin >> c[i][j];

		int cnt = 0;

		rep(i, h) rep(j, w) {
			if (c[i][j] == 1) {
				dfs(c, i, j);
				cnt++;
			}
		}

		cout << cnt << endl;
	}
}

C++: #include <iostream>

using namespace std;

#define MAX_H 55
#define MAX_W 55

int W, H;

int C[MAX_H][MAX_W];

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 x, int y)
{
	if (C[y][x] == 1)
	{
		C[y][x] = 0;

		for (int i = 0; i < 8; i++)
		{
			if (0 <= x + dx[i] && x + dx[i] <= W - 1 && 0 <= y + dy[i] && y + dy[i] <= H - 1)
			{
				if (C[y + dy[i]][x + dx[i]] == 1)
				{
					dfs(x + dx[i], y + dy[i]);
				}
			}
		}
	}
}

int main()
{
	while (true)
	{
		cin >> W >> H;

		if (W == 0 && H == 0) { break; }

		for (int i = 0; i < H; i++)
		{
			for (int j = 0; j < W; j++)
			{
				cin >> C[i][j];
			}
		}

		int count = 0;

		for (int i = 0; i < H; i++)
		{
			for (int j = 0; j < W; j++)
			{
				if (C[i][j] == 1)
				{
					dfs(j, i);

					count++;
				}
			}
		}

		cout << count << endl;
	}

	return 0;
}

C++: #include <cstdio>
#define f(n)for(int i=0;i<n;i++)
#define s(w)scanf("%d",&w)
int a,n,m,d[99][99];
int u[16]={-1,-1,-1,0,0,1,1,1,-1,0,1,-1,1,-1,0,1};
void k(int x,int y){
	if(d[x][y]){f(8)k(x+u[i],y+u[i+8]);d[x][y]=0;}
}
int main(){
	a=0;
	s(n);s(m);
	f(n*m)s(d[i/n][i%n]);
	f(n*m)if(d[i/n][i%n])a++,k(i/n,i%n);
	printf("%d\n",a);
	main();
}