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 <iostream>
#include <cstdio>
#include <cstring>
#include <climits>
#include <string>
#include <algorithm>
#include <cmath>
#include <vector>
#include <stack>
#include <queue>
#include <map>
#include <unordered_map>
#include <set>
#include <unordered_set>
#include <sstream>
#include <numeric>
// #include <boost/multiprecision/cpp_dec_float.hpp>
// #include <boost/multiprecision/cpp_int.hpp>

///////////////////////////////////////////////////////////////
// namespace
///////////////////////////////////////////////////////////////
using namespace std;
// namespace mp = boost::multiprecision;

///////////////////////////////////////////////////////////////
// types
///////////////////////////////////////////////////////////////
using pii = pair<int, int>;
using ll = long long int;
using ld = long double;
// using mpi = mp::cpp_int;
// using mpf = mp::number<mp::cpp_dec_float<1024>>;

///////////////////////////////////////////////////////////////
// mod https://qiita.com/drken/items/3b4fdf0a78e7a138cd9a
///////////////////////////////////////////////////////////////
// ll MOD = 1000000007;
// ll mod(long long val) {
//     long long res = val % MOD;
//     if (res < 0) res += MOD;
//     return res;
// }
// ll modinv(ll a) {
//     ll b = MOD, u = 1, v = 0;
//     while (b) {
//         ll t = a / b;
//         a -= t * b; swap(a, b);
//         u -= t * v; swap(u, v);
//     }
//     u %= MOD;
//     if (u < 0) u += MOD;
//     return u;
// }

int w, h;
vector<vector<int>> c;

bool dfs(int i, int j) {
    if (c[i][j] == 0) return false;
    c[i][j] = 0;
    if (i - 1 >= 0) dfs(i - 1, j);
    if (i + 1 < h) dfs(i + 1, j);
    if (j - 1 >= 0) dfs(i, j - 1);
    if (j + 1 < w) dfs(i, j + 1);
    if (i - 1 >= 0 && j - 1 >= 0) dfs(i - 1, j - 1);
    if (i - 1 >= 0 && j + 1 < w) dfs(i - 1, j + 1);
    if (i + 1 < h && j + 1 < w) dfs(i + 1, j + 1);
    if (i + 1 < h && j - 1 >= 0) dfs(i + 1, j - 1);
    return true;
}

bool solve() {
    cin >> w >> h;
    if (w == 0 && h == 0) return false;
    c = vector<vector<int>>(h, vector<int>(w));
    for (int i = 0; i < h; ++i) {
        for (int j = 0; j < w; ++j) {
            cin >> c[i][j];
        }
    }
    int ans = 0;
    for (int i = 0; i < h; ++i) {
        for (int j = 0; j < w; ++j) {
            ans += dfs(i, j);
        }
    }
    cout << ans << endl;
    return true;
}

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

C++: #include<bits/stdc++.h>
/*
#include<iostream>
#include<vector>
#include<algorithm>
 */
using namespace std;
typedef long long ll;
#define F first
#define S second
#define pii pair<int, int>
#define eb emplace_back
#define all(v) v.begin(), v.end()
#define rep(i, n) for (int i = 0; i < n; ++i)
#define rep3(i, l, n) for (int i = l; i < n; ++i)
#define chmax(a, b) a = (a >= b ? a : b)
#define chmin(a, b) a = (a <= b ? a : b)
#define out(a) cout << a << endl
#define outa(a, n) rep(_, n) cout << a[_] << " "; cout << endl
#define SZ(v) (int)v.size()
#define inf (int)(1e9+7)
#define abs(x) (x >= 0 ? x : -(x))
#define ceil(a, b) a / b + !!(a % b)
#define FIX(a) fixed << setprecision(a)

int h, w;
bool c[50][50];
int cnt;
int reached[50][50];
void dfs(int y, int x) {
    rep3(i, -1, 2) rep3(j, -1, 2) {
        if ((i | j) == 0) continue;
        int ny = y + i;
        int nx = x + j;
        if (ny < 0 || ny >= h || nx < 0 || nx >= w) continue;
        if (reached[ny][nx] == 1 || c[ny][nx] == 0) continue;
        reached[ny][nx] = 1;
        dfs(ny, nx);
    }
}
int main() {
    while (cin >> w && w) {
        cin >> h;
        fill_n(*reached, 50 * 50, 0);
        rep(i, h) rep(j, w) cin >> c[i][j];
        cnt = 0;
        rep(i, h) rep(j, w) {
            if (c[i][j] == 0 || reached[i][j] == 1) continue;
            reached[i][j] = 1;
            cnt++;
            dfs(i, j);
            // rep(k, h) { rep(l, w) cout << reached[k][l] << " "; cout << endl; }
        }
        out(cnt);
    }
}

C++: #include<iostream>

using namespace std;

int map[50][50];
int h,w;
int dx[]={-1,0,1},dy[]={-1,0,1};
void loop(int ,int );
int main(){
	int cnt=0;
	while(cin>>h>>w,h){
		for(int i=0;i<w;i++){
			for(int j=0;j<h;j++){
				cin>>map[i][j];
			}
		}
		for(int i=0;i<w;i++){
			for(int j=0;j<h;j++){
				if(map[i][j]==1){
					loop(i,j);	
					cnt++;	
				}
			}
		}
		cout<<cnt<<endl;
		for(int i=0;i<w;i++){
			for(int j=0;j<h;j++){
				map[i][j]=0;
			}
		}
	}
	return 0;
}
void loop(int x,int y){
	map[x][y]=0;
	for(int i=0;i<3;i++){
		for(int j=0;j<3;j++){
			if(map[x+dx[i]][y+dy[j]]==1){
				loop(x+dx[i],y+dy[j]);
			}
		}
	}
	return ;
}

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

int m[51][51];
bool v[51][51];
int h,w,c=0;
int dx[8]={-1,-1,0,1,1,1,0,-1};
int dy[8]={0,-1,-1,-1,0,1,1,1};
void dfs(int x,int y){
    if(v[y][x])return;
    for(int i=0;i<8;i++){
        int nx=x+dx[i];
        int ny=y+dy[i];
        if(nx>=0&&nx<w&&ny>=0&&ny<h&&!v[y][x]&&m[ny][nx]){
            dfs(nx,ny);
        }
    }
}
int main(){
    cin>>h>>w;
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            cin>>m[i][j];
            v[i][j]=0;
        }
    }
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            if(!v[i][j]&&m[i][j]){
                dfs(i,j);
                c++;
            }
        }
    }
    cout<<c<<endl;
}