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>
#define debug(x) cerr << #x << ": " << x << '\n';
using namespace std;
using ll = long long;
using P = pair<int, int>;
const int INF = (int)1e9;

int w, h;
int c[51][51];
int dx[] = {1, -1, 0, 0, 1, 1, -1, -1};
int dy[] = {0, 0, 1, -1, 1, -1, 1, -1};

void dfs(int y, int x){
	c[y][x] = 0;
	for(int i = 0; i < 8; i++){
		int ny = y + dy[i], nx = x + dx[i];
		if(0<=ny and ny<h and 0<=nx and nx<w and c[ny][nx]==1){
			dfs(ny, nx);
		}
	}
}

int solve(){
	int res = 0;
	for(int i = 0; i < h; i++){
		for(int j = 0; j < w; j++){
			if(c[i][j] == 1){
				dfs(i, j);
				res++;
			}
		}
	}

	return res;
}

int main(void){
	while(scanf("%d%d", &w, &h) != EOF){
		if(w == 0 and h == 0) break;
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				scanf("%d", &(c[i][j]));
			}
		}
		printf("%d\n", solve());
	}

	return 0;
}

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

int h,w;
int mas[60][60];

void solve(int x,int y){
  for(int i=-1;i<=1;i++){
    for(int j=-1;j<=1;j++){
      int nx = x + i;
      int ny = y + j;
      if(nx >= 0 && ny >= 0 && nx < w && ny < h && mas[ny][nx] == 1){
	mas[ny][nx] = 0;
	solve(nx,ny);
      }
    }
  }
  return;
}

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

C++: #include <iostream>
#include <vector>
#include <algorithm>
#include <string>

#define REP(i, a, b) for (int i = int(a); i < int(b); i++)
#define dump(val) cerr << __LINE__ << ":\t" << #val << " = " << (val) << endl

using namespace std;

typedef long long int ll;

template<typename T>
vector<T> make_v(size_t a, T b) {
    return vector<T>(a, b);
}

template<typename... Ts>
auto make_v(size_t a, Ts... ts) {
    return vector<decltype(make_v(ts...))>(a, make_v(ts...));
}

void dfs(int y, int x, vector<vector<bool>> &used, vector<vector<int>> &M) {
    if (used[y][x]) return;
    used[y][x] = true;
    REP(i, -1, 2) {
        REP(j, -1, 2) {
            int ny = y + i, nx = x + j;
            if (ny < 0 || ny >= M.size() || nx < 0 || nx >= M[ny].size() || M[ny][nx] == 0) continue;
            dfs(ny, nx, used, M);
        }
    }
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int w, h;
    while (cin >> w >> h, w + h) {
        auto M = make_v(h, w, 0);
        REP(i, 0, h) {
            REP(j, 0, w) {
                cin >> M[i][j];
            }
        }
        auto used = make_v(h, w, false);
        int ans = 0;
        REP(i, 0, h) {
            REP(j, 0, w) {
                if (!used[i][j] && M[i][j] == 1) {
                    dfs(i, j, used, M);
                    ans++;
                }
            }
        }
        cout << ans << endl;
    }

    return 0;
}

C++: //41
#include<iostream>

using namespace std;

int w,h;
bool imap[50][50];

void ff(int y,int x){
  imap[y][x]=false;
  for(int i=-1;i<=1;i++){
    for(int j=-1;j<=1;j++){
      if(imap[y+i][x+j]){
	ff(y+i,x+j);
      }
    }
  }
}

int main(){
  for(;cin>>w>>h,w|h;){
    fill_n(&imap[0][0],50*50,false);
    for(int y=0;y<h;y++){
      for(int x=0;x<w;x++){
	cin>>imap[y][x];
      }
    }
    int ans=0;
    for(int y=0;y<h;y++){
      for(int x=0;x<w;x++){
	if(imap[y][x]){
	  ans++;
	  ff(y,x);
	}
      }
    }
    cout<<ans<<endl;
  }
  return 0;
}