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>
using namespace std;

#define REP(i, n) for(int i = 0; i < n; i++)
#define REPR(i, n) for(int i = n; i >= 0; i--)
#define FOR(i, m, n) for(int i = m; i < n; i++)
#define ALL(obj) (obj).begin(), (obj).end()
#define INF 1e9
typedef long long ll;


vector<int> dx{-1,0,1};
vector<int> dy{-1,0,1};

vector<vector<int>> G;
int w,h;

void dfs(vector<vector<int>> &G, int x, int y){
    if (G[y][x] == 1){
        G[y][x] = 0;

        REP(i,3){
            REP(j,3){
                int next_x = x+dx[i];
                int next_y = y+dy[j];
                if (i==1 && j==1)continue;
                if (0<=next_x && next_x<w && 0<=next_y && next_y<h){
                    dfs(G, next_x, next_y);
                }
            }
        }
    }
}

int main() {
    while(1){
        
        cin >> w >> h;
        if(w==0 && h==0) break;
        G.assign(h, vector<int>(w, 0));
        REP(i,h){
            REP(j,w){
                cin >> G[i][j];
            }
        }

        int count = 0;
        REP(i,h){
            REP(j,w){
                if (G[i][j] == 1){
                    count ++;
                    dfs(G, j, i);//G,w,h
                
                }
            }
        }
        cout << count << endl;
    }
    return 0;
}

C++: // テ・ツ淞コテヲツ慊ャテ」ツδ?」ツδウテ」ツδ療」ツδャテ」ツδシテ」ツδ?(テァツクツョテ・ツーツ湘ァツ可?

#include <bits/stdc++.h>
using namespace std;
#define rep(i,a,n) for(int (i)=(a); (i)<(n); (i)++)
#define repq(i,a,n) for(int (i)=(a); (i)<=(n); (i)++)
#define repr(i,a,n) for(int (i)=(a); (i)>=(n); (i)--)
#define int long long
template<typename T> void chmax(T &a, T b) {a = max(a, b);}
template<typename T> void chmin(T &a, T b) {a = min(a, b);}
template<typename T> void chadd(T &a, T b) {a = a + b;}
typedef pair<int, int> pii;
typedef long long ll;
constexpr ll INF = 1001001001001001LL;
constexpr ll MOD = 1000000007LL;

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

int W, H;
int board[60][60];
bool used[60][60];

signed main() {
    while(cin >> W >> H, W || H) {
        memset(used, false, sizeof(used));
        rep(i,0,H) rep(j,0,W) cin >> board[i][j];

        int ans = 0;
        rep(i,0,H) rep(j,0,W) {
            if(used[i][j] || board[i][j] == 0) continue;
            ans++; used[i][j] = true;

            queue<pii> q;
            q.push(pii(i, j));

            while(!q.empty()) {
                pii t = q.front(); q.pop();
                int x = t.first, y = t.second;
                rep(k,0,8) {
                    int nx = x + dx[k], ny = y + dy[k];
                    if(nx < 0 || nx >= H || ny < 0 || ny >= W) continue;
                    if(used[nx][ny] || board[nx][ny] == 0) continue;
                    used[nx][ny] = true;
                    q.push(pii(nx, ny));
                }
            }
        }
        cout << ans << endl;
    }
    return 0;
}

C++: #include <bits/stdc++.h>

using namespace std;

#define llong long long 
int w,h;
int sum;
int area[50][50];
int nw[8] = {0, 1, 1, 1, 0, -1, -1, -1};
int nh[8] = {1, 1, 0, -1, -1, -1, 0, 1};

void solve(int h, int w){
	if(area[h][w] == 0)return;
	area[h][w] == 0;
	for(int i = 0; i < 8; i++){
		int sh = h + nh[i];
		int sw = w + nw[i];
		if(sh < 0 || sw < 0 || sh >= h || sw >= w) continue;
		solve(sh, sw);
	}
	return;
}

int main(){

	while(cin >> w >> h, w){
		sum = 0;
		fill_n(*area, 50 * 50, 0);
		for(int i = 0; i < h; i++){
			for(int j = 0; j < w; j++){
				cin >> area[i][j];
			}
		}	

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

		cout << sum << endl;
}
	return 0;
}

C++: #include<iostream>
#include<cstdio>
#include<algorithm>
using namespace std;
int island[50][50];
void func(int,int);

int main(){
  int w,h;
  int ans;
  
  while(1){
    cin>>w>>h;
    if(w==0 && h==0) break;
    ans=0;
    
    for(int i=0;i<h;i++){
      for(int l=0;l<w;l++){
        cin>>island[i][l];
      }
    }
    
    for(int i=0;i<h;i++){
      for(int l=0;l<w;l++){
        if(island[i][l]==1){
          func(i,l);
          ans++;
        }
      }
    }
    printf("%d\n",ans);
  }
  return 0;
}

void func(int x,int y){
  island[x][y]=0;
  for(int i=x-1;i<x+2;i++){
    for(int l=y-1;l<y+2;l++){
      if(island[i][l]==1)
        func(i,l);
    }
  }
}

C++: #include <iostream>

using namespace std;

int W,H;

bool table[50][50];


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

void dfs(int x,int y){
	table[x][y]=0;
	for(int i=0;i<8;i++){
		if(0<=x+dx[i]&&x+dx[i]<W&&0<=y+dy[i]&&y+dy[i]<H&&table[x+dx[i]][y+dy[i]])
			dfs(x+dx[i],y+dy[i]);
	}
	return ;
}


int main(void){
	while(cin >> W >> H,W|H){
		for(int y=0;y<H;y++)
			for(int x=0;x<W;x++)
				cin >> table[x][y];
		int num=0;
		for(int y=0;y<H;y++)
			for(int x=0;x<W;x++)
				if(table[x][y])
					num++,dfs(x,y);
		cout << num << endl;
	}
	return 0;
}

C++: #include<stdio.h>
#include<iostream>

int field[51][51];
int w,h;

void land(int x,int y){
	field[x][y]=0;

	for(int yy=-1;yy<=1;yy++){
		for(int xx=-1;xx<=1;xx++){
			if(x+xx>=0&&x+xx<=w&&y+yy>=0&&y+yy<=h){
			   if(field[x+xx][y+yy]==1) land(x+xx,y+yy);
			}
		}
	}
	return;
}

int main(void){

	int kazu=0;

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

	if(w==0||h==0) return 0;

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

	for(int i=0;i<h;i++){
		for(int j=0;j<w;j++){

			if(field[j][i]==1){
				land(j,i);
				kazu++;
			}

		}
	}

	printf("%d",kazu);
	return 0;
}