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 <cstdio>
#include <cstdlib>
#include <cmath>
#include <cstring>

#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <queue>
#include <stack>
#include <map>
#include <set>

#include <functional>
#include <cassert>

typedef long long ll;
using namespace std;

#define mod 1000000007 //1e9+7
#define INF 1000000000 //1e9
#define LLINF 2000000000000000000LL //2e18
#define SIZE 201

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

int mm[SIZE][SIZE];
int h,w;

bool dfs(int y,int x){
  
  if(y<0 || h<=y || x<0 || w<=x) return false;
  if(mm[y][x]==0) return false;
  mm[y][x] = 0;
  
  for(int i=0;i<8;i++){
    dfs(y+dy[i],x+dx[i]);
  }

  return true;
}

void calc(){
  int ans = 0;

  for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
      scanf("%d",mm[i]+j);
    }
  }

  for(int i=0;i<h;i++){
    for(int j=0;j<w;j++){
      ans += dfs(i,j);
    }
  }
  
  printf("%d\n",ans);
}

int main(){
  
  while(1){
    scanf("%d%d",&w,&h);
    if(h==0) break;
    calc();
  }
  
  return 0;
}

C++: #include <iostream>
#include <cstdio>
using namespace std;
#define N 50

const int dx[]={-1,-1,-1,0,0,1,1,1};
const int dy[]={-1,0,1,-1,1,-1,0,1};
int w,h;
int map[N][N];

void rec(int y,int x){
	map[y][x]=0;
	for(int i=0;i<8;i++){
		int nextx = x + dx[i];
		int nexty = y + dy[i];
		if(nextx>=0&&nexty>=0&&nextx<w&&nexty<h){
			if(map[nexty][nextx]==1){
				rec(nexty,nextx);
			}
		}
	}

}
	

int main(){

	while(cin >> w >> h){
		if(w==0&&h==0) break;
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				scanf("%d",&map[i][j]);
			}
		}
	
		int count=0;
	
		for(int i=0;i<h;i++){
			for(int j=0;j<w;j++){
				if(map[i][j]==1){
					rec(i,j);
					count++;
				}
			}
		}
		cout<<count<<endl;
	}

	return 0;
}

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

using namespace std;

bool base[50][50] = {};

void dfs( int const y, int const x, int const w, int const h )
{
  if ( x >= 0 && y >= 0 && x < w && y < h && base[y][x] ) {
      base[y][x] = false;
      dfs( y + 1, x, w, h );
      dfs( y - 1, x, w, h );
      dfs( y, x + 1, w, h );
      dfs( y, x - 1, w, h );
      dfs( y + 1, x + 1, w, h );
      dfs( y - 1, x - 1, w, h );
      dfs( y - 1, x + 1, w, h );
      dfs( y + 1, x - 1, w, h );
  }
}


int main()
{
  for(;;) {
    
    int w, h;
    cin >> w >> h;

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

    for( int i=0; i<50; ++i )
      for( int j=0; j<50; ++j )
	base[i][j] = false;

    for( int i=0; i<h; ++i )
      for( int j=0; j<w; ++j )
	cin >> base[i][j];

    int count = 0;
    for( int i=0; i<h; ++i ) {
      for( int j=0; j<w; ++j ) {
	if ( base[i][j] ) {
	  dfs( i, j, w, h );
	  ++count;
	}
      }
    }
    
    cout << count << endl;
  }
}

C++: # include <iostream>

const int MAX_W = 50;
const int MAX_H = 50;

int w, h;

int c[MAX_H][MAX_W];

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

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

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

int main() {
	while (1) {
		std::cin >> w >> h;
		if ((w + h) == 0)
			break;
		for (int i = 0; i < h; ++i) {
			for (int j = 0; j < w; ++j)
				std::cin >> c[i][j];
		}
		std::cout << solve() << std::endl;
	}
	return 0;
}

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 <iostream>
using namespace std;

int ans,w,h,I[55][55];//??????

void dfs(int x,int y){
	I[x][y]=0;
	for(int i=-1;i<=1;i++){
		for(int j=-1;j<=1;j++){
			if(I[x+i][y+j]==1)dfs(x+i,y+j);
		}
	}
}
int main(){
	while(1){
		cin>>w;
		cin>>h;
		if(w==0&&h==0)break;
		ans=0;
		for(int i=0;i<55;i++){
			for(int j=0;j<55;j++){
				I[i][j]=0;
			}
		}
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				cin>>I[i][j];
			}
		}
		for(int i=1;i<=h;i++){
			for(int j=1;j<=w;j++){
				if(I[i][j]==1){
					dfs(i,j);
					ans++;
				}
			}
		}
		cout<<ans<<endl;
	}
	return 0;
}