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 FOR(i, s, n) for(int i = s; i < (int)n; i++)
#define per(i, n) for(int i = n; i >= 0; i--)
#define ROF(i, s, n) for(int i = s; i >= (int)n; i--)
#define FORIT(i, A) for (auto i : A)
#define PRINT(x) cout << (x) << "\n"
#define ALL(a) (a).begin(),(a).end()
#define RALL(a) (a).rbegin(), (a).rend()
#define MP make_pair
#define EACH(i, n) for (__typeof((n).begin()) i = (n).begin(); i != (n).end(); ++i)
#define SZ(a) int((a).size())
#define EXIST(s,e) ((s).find(e)!=(s).end())
#define SORT(c) sort((c).begin(),(c).end())
#define CLR(a) memset((a), 0 ,sizeof(a))
#define dump(x) cout << #x << " = " << (x) << "\n";
#define debug(x) cout << #x << " = " << (x) << " (L" << __LINE__ << ")" << " " << __FILE__ << "\n";
#define sq(n) (n) * (n)
typedef vector<int> VI;
typedef vector<VI> VVI;
typedef vector<string> VS;
typedef pair<int, int> PII;
typedef long long LL;
typedef vector<LL> VLL;
typedef vector<VLL> VVLL;
typedef unsigned int uint;
typedef unsigned long long ull;
typedef priority_queue<int> maxpq;
typedef priority_queue< int, vector<int>, greater<int> > minpq;
static const double EPS = 1e-10;
static const double PI = acos( -1.0 );
static const int mod = 10007;
static const int INF = 1 << 25;
static const LL LL_INF = 1152921504606846976;
static const int dx[] = { 1, -1, 0, 0,  1, -1,  1, -1 };
static const int dy[] = { 0, 0, 1, -1 , 1,  1, -1, -1 };

string str;
int w, h, ans;
VVI ar;

int gcd( int m, int n ) {
	if ( n == 0 ) return m;
	return gcd( n, m % n );
}

void solve( int y, int x ) {
	ar[ y ][ x ] = 0;
	for ( int i = 0; i < 8; i++ ) {
		if ( ar[ y + dy[ i ] ][ x + dx[ i ] ] ) {
			solve( y + dy[ i ], x + dx[ i ] );
		}
	}
}

int main() {
	while ( ~scanf("%d %d", &w, &h) && w && h ) {
		ar.resize( h + 2 );
		for ( int i = 0; i < h + 2; i++ ) {
			ar[ i ].resize( w + 2 );
		}
		ans = 0;
		for ( int i = 0; i < w + 2; i++ ) {
			ar[ 0 ][ i ] = 0;
			ar[ h + 1 ][ i ] = 0;
		}
		for ( int i = 1; i < h + 1; i++ ) {
			for ( int j = 1; j < w + 1; j++ ) {
				scanf( "%d", &ar[ i ][ j ] );
			}
		}
		for ( int i = 0; i < h + 2; i++ ) {
			for ( int j = 0; j < w + 2; j++ ) {
				if ( ar[ i ][ j ] ) {
					ans++;
					solve( i, j );
				}
			}
		}
		printf( "%d\n", ans );
		ar.clear();
	}
	return 0;
}

C++: #include <stdio.h>
#include <iostream>
#include <algorithm>
#include <functional>
#include <cstdlib>
#include <sstream>
#include <string>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <complex>
#include <vector>
#include <cstdio>
#include <math.h>
#include <cmath>
#include <time.h>
#define all(c) ((c).begin(),(c).end())
#define rall(c) (c).rbegin(),(c).rend()
#define sort(v,n) sort(v,v+n)
#define vsort(v) sort(v.begin(),v.end())
#define vvsort(v) sort(v.begin(),v.end(),greater<int>())
#define ll long long
#define pb(a) push_back(a)
#define fi first
#define se second
#define inf 999999999
using namespace std;
const ll MOD = 1e9 + 7;
const double PI = acos(-1.0);
//---------------------------------------------------------------------------------------------//
int w, h;
bool c[55][55];
int ans=0;

void dfs(int nowy, int nowx) {
	c[nowy][nowx] = 0;
	for (int i = -1; i < 2; i++) {
		for (int j = -1; j < 2; j++) {
			if (nowy == 0 && i == -1)continue;
			if (nowx == 0 && j == -1)continue;
			if (nowy == h - 1 && i == 1)continue;
			if (nowx == w - 1 && j == 1)continue;
			if (c[nowy + i][nowx + j] == 1) {
				dfs(nowy + i, nowx + j);
			}
		}
	}
}



int main() {
	while (cin >> w >> h, w) {
		ans = 0;
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				cin >> c[i][j];
			}
		}
		for (int i = 0; i < h; i++) {
			for (int j = 0; j < w; j++) {
				if (c[i][j] == 1) {
					dfs(i, j);
					ans++;
				}
			}
		}
		cout << ans << endl;
	}
}