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<vector>

using namespace std;

int w,h;
bool field[50][50];
vector<int> ans;

void dfs(int i,int j);

int main(){
	while(1){
		for(int i = 0;i < 50;i++){
			for(int j = 0;j < 50;j++){
				field[i][j] = false;
			}
		}
		cin >> w >> h;
		if(w + h == 0) break;
		for(int i = 0;i < h;i++){
			for(int j = 0;j < w;j++){
				int f;
				cin >> f;
				if(f == 1) field[i][j] = true;
			}
		}
		int count = 0;
		for(int i = 0;i < h;i++){
			for(int j = 0;j < w;j++){
				if(field[i][j]){dfs(i,j);count++;}
			}
		}
		ans.push_back(count);
	}
	for(int i = 0;i < ans.size();i++) cout << ans[i] << endl;
	return 0;
}

void dfs(int i,int j){
	field[i][j] = false;
	if(i != 0 	&& j != 0 	&& field[i-1][j-1])dfs(i-1,j-1);
	if(i != 0 				&& field[i-1][j])dfs(i-1,j);
	if(i != 0 	&& j != w-1 && field[i-1][j+1])dfs(i-1,j+1);
	if(			   j != w-1 && field[i][j+1])dfs(i,j+1);
	if(i != h-1 && j != w-1 && field[i+1][j+1])dfs(i+1,j+1);
	if(i != h-1 			&& field[i+1][j])dfs(i+1,j);
	if(i != h-1 && j != 0 	&& field[i+1][j-1])dfs(i+1,j-1);
	if(			   j != 0 	&& field[i][j-1])dfs(i,j-1);
}

C++: #include<iostream>
#include<cstdio>
using namespace std;
int mas[100][100];
int dx[8]={1,1,0,-1,-1,-1,0,1},dy[8]={0,1,1,1,0,-1,-1,-1};
int sx,sy,gx,gy,w,h,cnt=0;
void dfs(int x,int y);
int main(){
  while(1){
    cnt=0;
  cin >> w >> h;
  if(w==0 && h==0) break;
  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){
        cnt++;
        dfs(j,i);
      }
    }
  }
  cout << cnt << endl;
  }
}
void dfs(int x,int y){
  mas[y][x]=0;
  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 && mas[ny][nx]==1){
        dfs(nx,ny);
      }
  }
}

C++: #include<iostream>
#include<cstring>
#include<string>
#include<algorithm>
#include<cmath>
#include<vector>
using namespace std;
typedef long long ll;
#define rep(i,s,n) for(int i = s;i<n;i++)
#define repe(i,s,n) for(int i = s;i<=n;i++)
static const ll maxLL = (ll)1 << 62;

//dfs(bool型)
int dy[]={-1,0,1,0,1,-1,-1,1};
int dx[]={0,1,0,-1,1,1,-1,-1};
bool visited[1000][1000];
int t[1000][1000];
char copy_t[1000][1000];
int h,w;
int si,sj;

void dfs(int y,int x){
  if(y<=0||x<=0)return;
  if(y>h||x>w)return;
  if(t[y][x]==0)return;
  if(visited[y][x])return;
  visited[y][x]=true;
  for(int i=0;i<8;i++){
    int ny=y+dy[i];
    int nx=x+dx[i];
    dfs(ny,nx);
  }
  return;
}

int main(){
    int cnt=0;
    cin>>w>>h;
    repe(i,1,h){
        for(int j=1;j<=w;j++){
            cin>>t[i][j];
        }
    }
    repe(i,1,h){
        repe(j,1,w){
             if(t[i][j]==1 && visited[i][j]==false)cnt++;
        dfs(i,j);
        }
    }
    cout<<cnt<<endl;
    return 0;
}

C++: #include<cstdio>
using namespace std;
void func(int,int);
int a,b;
int sima[51][51];
int cnt;
int y,x;
int main(void)
{
	int i,j;
	scanf("%d",&a);
	scanf("%d",&b);
	while(!(a==0 && b==0)){
		
		for(i=0;i<b;i++){
			for(j=0;j<a;j++){
				scanf("%d",&sima[i][j]);
			}
		}
		cnt=0;
		for(i=0;i<b;i++){
			for(j=0;j<a;j++){
				if(sima[i][j]==1){
					func(i,j);
					cnt++;
				}
			}
		}
		printf("%d\n",cnt);
		scanf("%d",&a);
		scanf("%d",&b);
	}
	return 0;
}
void func(int y,int x)
{
	if(y-1>=0){
		if(sima[y-1][x]==1){
			sima[y-1][x]=0;
			func(y-1,x);
		}
	}
	if(x-1>=0){
		if(sima[y][x-1]==1){
			sima[y][x-1]=0;
			func(y,x-1);	
		}
	}
	if(y+1<=a){
		if(sima[y+1][x]==1){
			sima[y+1][x]=0;
			func(y+1,x);
		}
	}
	if(x+1<=b){
		if(sima[y][x+1]==1){
			sima[y][x+1]=0;
			func(y,x+1);
		}
	}
	if(y-1>=0 && x+1<=b){
		if(sima[y-1][x+1]==1){
			sima[y-1][x+1]=0;
			func(y-1,x+1);
		}
	}
	if(y-1>=0 && x-1>=0){
		if(sima[y-1][x-1]==1){
			sima[y-1][x-1]=0;
			func(y-1,x-1);
		}
	}
	if(y+1<=a && x+1<=b){
		if(sima[y+1][x+1]==1){
			sima[y+1][x+1]=0;
			func(y+1,x+1);
		}
	}
	if(y+1<=a && x-1>=0){
		if(sima[y+1][x-1]==1){
			sima[y+1][x-1]=0;
			func(y+1,x-1);
		}
	}
}

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

int dx[8]={0,1,1,1,0,-1,-1,-1};
int dy[8]={1,1,0,-1,-1,-1,0,1};
int d[55][55];

void init(){
  for(int i=0;i<55;i++)for(int j=0;j<55;j++)d[i][j]=0;
}

void Delete(int sx,int sy,int h,int w){
  queue<int>que;
  que.push(sx);que.push(sy);
  while(que.size()){
    int x=que.front();que.pop();
    int y=que.front();que.pop();
    for(int i=0;i<8;i++){
      if(d[y+dy[i]][x+dx[i]]==1&&0<=y+dy[i]&&y+dy[i]<h&&0<=x+dx[i]&&x+dx[i]<w){
	d[y+dy[i]][x+dx[i]]=0;
	que.push(x+dx[i]);
	que.push(y+dy[i]);
      }
    }
  }
}

int solve(int w,int h){
  int cnt=0;
  for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
      if(d[i][j]==1){
	Delete(j,i,h,w);
	cnt++;
      }
    }
  }
  return cnt;
}

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