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>
void printmap();
void draw(int x,int y);
int w,h,c[50][50];

int main(){
	int i,j;
	int count;


	scanf("%d %d",&w,&h);


	while((w!=0)&&(h!=0)){
		count=0;
	
		for(j=0;j<h;j++){
			for(i=0;i<w;i++){
				scanf("%d",&c[j][i]);
			}
		}
		//printf("\n");
		
		for(i=0;i<w;i++){
			c[h][i]=0;
		}
		for(i=0;i<h;i++){
			c[i][w]=0;
		}

		for(i=0;i<w;i++){
			for(j=0;j<h;j++){
				if(c[j][i]==1){
					count++;
					//printf("count up count=%d\n",count);
					draw(j,i);
					//printmap();
				}
			}
		}

		printf("%d\n",count);
		scanf("%d %d",&w,&h);
	}
	return 0;
}

void draw(int x,int y){
	//printf("delete %d %d\n",x,y);
	int i,j;
	c[x][y]=0;
	for(i=0;i<3;i++){
		for(j=0;j<3;j++){
			if(c[x-1+i][y-1+j]==1){
				draw(x-1+i,y-1+j);
			}
		}
	}


}

void printmap(){
	int i,j;
	for(j=0;j<h;j++){
		for(i=0;i<w;i++){
			printf("%d ",c[j][i]);
		}
		printf("\n");
	}
}

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

using namespace std;


int read_map(vector< vector <int> >& map,int &w, int &h){
  cin >> w >>  h;
  if (w == 0 && h == 0){
    return 0;
  }
  map.reserve(h);
  for (int i = 0; i < h ; ++i) map[i].resize(w);
  for (int i = 0; i < h; ++i)
  {
    for (int j = 0; j < w; ++j)
    {
      cin >> map[i][j];
    }
  }
  return 1;
}


bool island_check(vector<vector<int> >& map, int i, int j){
  if (map[i][j] == 1){
    return true;
  }
  return false;
}

void walk_island(vector<vector<int> >& map, int i, int j, int w, int h){
  int start_i, start_j;
  start_i = i;
  start_j = j;
  while (++j < w){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (--j >= 0){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (++i < h){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (--i >= 0){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (++i < h && ++j < w){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (--i >= 0 && ++j < w){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (--i >= 0 && --j >= 0){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (++i < h && --j >= 0){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
}

int search_island_num(vector< vector <int> >& map, int w, int h){
  int island_count = 0;
  for (int i = 0; i < h; ++i)
  {
    for (int j = 0; j < w; ++j)
    {
      if(map[i][j] == 1){
        island_count++ ;
        map[i][j] = 2;
        walk_island(map, i, j, w, h);
      }
    }
  }
  return island_count;
}

int main(){
  vector< vector<int> > map;
  int w, h;
  while (read_map(map, w, h) != 0) {
    cout << search_island_num(map, w, h) << endl;
    map.clear();
  }
}

C++: #include<iostream>
#include<iomanip>
#include<math.h>
#include<vector>
#include<algorithm>
#include<set>
#include<map>
#include<queue>
#include<stack>
#include<string>
#include<time.h>
#define INF 1000000000ll
#define MOD 1000000007ll
#define EPS 1e-10
#define REP(i,m) for(long long i=0; i<m; i++)
#define FOR(i,n,m) for(long long i=n; i<m; i++)
#define DUMP(a) for(long long dump=0; dump<(ll)a.size(); dump++) { cout<<a[dump]; if(dump!=n-1) cout<<" "; else cout<<endl; }
#define ALL(v) v.begin(),v.end()
#define pb push_back
using namespace std;
typedef long long ll;
typedef pair<ll, ll> P;
typedef long double ld;

/*
 貪欲
 ?決定問題 必ず解に含まれる(含むように変換できる)ものから決めていく みんプロ本選B
 ?最適化問題 任意の解から評価を落とさず解に含められるようなものから決めていく 区間スケジューリングとか
 ?
 */

/*
 DP
 ?DPはある程度決め打ちをするべき(解を帰納的に構成できないか？)
 */

void dfs(ll i, ll j, vector<vector<int>>& c) {
	c[i][j]=0;
	for(ll dx=-1; dx<=1; dx++) {
		for(ll dy=-1; dy<=1; dy++) {
			if(i+dx>=0&&i+dx<(ll)c.size()&&j+dy>=0&&j+dy<=(ll)c[0].size()&&c[i+dx][j+dy]==1) dfs(i+dx,j+dy,c);
		}
	}
}

int main() {
	cin.tie(0);
	ios::sync_with_stdio(false);
	while(1) {
	ll w,h;
	cin>>w>>h;
		if(w==0&&h==0) break;
	vector<vector<int>> c(h,vector<int>(w));
	REP(i,h) REP(j,w) cin>>c[i][j];
	ll ret=0;
	REP(i,h) REP(j,w) {
		if(c[i][j]==1) {
			ret++;
			dfs(i,j,c);
		}
	}
	cout<<ret<<endl;
	}
}