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 <stdio.h>

int W,H,ans;
int map[100][100];

void search_island(int x, int y){
	map[x][y] = 0;
	if(x > 0){
		if(map[x - 1][y]){
			search_island(x - 1, y);
		}
		if(y > 0){
			if(map[x - 1][y - 1]){
				search_island(x - 1, y - 1);
			}
		}
		if(y < W - 1){
			if(map[x - 1][y + 1]){
				search_island(x - 1, y + 1);
			}
		}
	}
	if(x < H - 1){
		if(map[x + 1][y]){
			search_island(x + 1, y);
		}
		
		if(y > 0){
			if(map[x + 1][y - 1]){
				search_island(x + 1, y - 1);
			}
		}
		if(y < W - 1){
			if(map[x + 1][y + 1]){
				search_island(x + 1, y + 1);
			}
		}
	}
	if(y > 0){
		if(map[x][y - 1]){
			search_island(x, y - 1);
		}
	}
	if(y < W - 1){
		if(map[x][y + 1]){
			search_island(x, y + 1);
		}
	}
}


int main()
{
	scanf("%d %d",&W,&H);
	while(W != 0 && H != 0){
		for(int i = 0; i < H; i++){
			for(int k = 0; k < W; k++){
				scanf("%d",&map[i][k]);
			}
		}

		ans = 0;

		for(int j = 0; j < H; j++){
			for(int k = 0; k < W; k++){
				if(map[j][k]){
					ans++;
					search_island(j,k);
				}
			}
		}

		printf("%d\n",ans);
		scanf("%d %d",&W,&H);
	}
	return 0;
}

C++: #include <bits/stdc++.h>
using namespace std;
// define
#define endl "\n"
#ifdef LOCAL
#define lout cerr
#else
ostream devnull(0);
#define lout devnull
#endif
#define AMULET \
  cin.tie(0);  \
  ios::sync_with_stdio(false);
// https://github.com/kurokoji/.cpp-Template/blob/master/template/template2.cpp
#define GET_MACRO(_1, _2, _3, _4, NAME, ...) NAME
#define rep(...) GET_MACRO(__VA_ARGS__, rep4, rep3, rep2, rep1) \
(__VA_ARGS__)
#define rep1(n) rep2(_, n)
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, a, n) rep4(i, a, n, 1)
#define rep4(i, a, n, d) rep5(i, a, n, d, <)
#define rep5(i, a, n, d, o) for (auto i = decltype(n)(a), _n = (n); i o _n; i += (d))

#define rrep(...) GET_MACRO(__VA_ARGS__, rrep4, rrep3, rrep2, rrep1) \
(__VA_ARGS__)
#define rrep1(a) rrep2(_, a)
#define rrep2(i, a) rrep3(i, a, 0)
#define rrep3(i, a, n) rrep4(i, a, n, -1)
#define rrep4(i, a, n, d) rep5(i, (a)-1, n, d, >=)

#define dump(x) lout << #x << " = " << x << endl;
// alias
typedef long long ll;
typedef long long lint;
typedef pair<int, int> pii;
typedef pair<lint, lint> pll;
// func
template <class C>
inline void vcin(C &c);
template <class C, class D>
inline void vcin(C &c, D &d);
template <class C>
inline void vcout(const C &c, const string separate = "\n");
template <class T = int>
inline T in();

int w, h;
int c[50][50];

void dfs(int x, int y);

void solve()
{
  while (true)
  {
    cin >> w >> h;

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

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

    int cnt = 0;
    rep(j, h) rep(i, w) if (c[i][j] == 1)
    {
      dfs(i, j);
      cnt++;
    }

    cout << cnt << endl;
  }
}

void dfs(int x, int y)
{
  c[x][y] = 0;
  rep(dy, -1, 2) rep(dx, -1, 2)
  {
    int nx = x + dx;
    int ny = y + dy;
    if (nx >= 0 && ny >= 0 && nx < w && ny < h && c[nx][ny] == 1)
    {
      dfs(nx, ny);
    }
  }
}

signed main()
{
  AMULET
  solve();
  return 0;
}

template <class C>
inline void vcin(C &c)
{
  for (auto &a : c)
  {
    cin >> a;
  }
}
template <class C, class D>
inline void vcin(C &c, D &d)
{
  for (auto it1 = c.begin(), it2 = d.begin(); it1 != c.end() && it2 != d.end(); it1++, it2++)
  {
    cin >> *it1 >> *it2;
  }
}
template <class C>
inline void vcout(const C &c, const string separate)
{
  for (auto it = c.begin(); it != c.end(); it++)
  {
    if (it != c.begin())
      cout << separate;
    cout << *it;
  }
}
template <class T = int>
inline T in()
{
  T x;
  cin >> x;
  return (x);
}

C++: #include<bits/stdc++.h>
#define rep(i,n) for(int i = 0;i<n;i++)
using namespace std;
typedef pair<int,int> P;
typedef long long ll;
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;}

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

void dfs(int x,int y) {
    for(int dx = -1;dx<=1;dx++) {
        for(int dy = -1;dy<=1;dy++) {
            int nx = x + dx;
            int ny = y + dy;
            if(nx<0 || nx>=h || ny<0 || ny>=w) continue;
            if(c[nx][ny] == 0) continue;
            if(c[nx][ny] == 1) c[nx][ny] = 0;
            dfs(nx,ny);
        }
    }
}

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] == 1) {
                ans++;
                dfs(i,j);
            }
        }
        cout << ans << endl;
    }    
}

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

#define rep(i,n) for(int i=0; i<n; i++)

short map[50][50];
int w, h;

void dfs(int x, int y) {
    map[x][y] = 0;
    int d[3] = {-1,0,1};
    rep(i, 9) {
        int xx = x+d[i%3];
        int yy = y+d[i/3];
        if( 0<=xx && xx<w && 0<=yy && yy<h && map[xx][yy]==1 ) {
            dfs( xx, yy );
        }
    }
}

int main(){
    while( cin >> w >> h, w||h ) {
        int lands = 0;
        rep(y,h) rep(x,w) cin >> map[x][y];
        rep(y, h) {
            rep(x, w) {
                if( map[x][y] == 1 ) {
                    lands++;
                    dfs(x, y);
                }
            }
        }
        cout << lands << endl;
    }
    return 0;
}