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<queue>
using namespace std;

struct mapst {
	int x, y;
};

int main() {
	int w, h, ans=0;
	int c[52][52]={{0}}, f[52][52]={{1}};
	int dx[8] = {-1, -1, 0, 1, 1, 1, 0, -1};
	int dy[8] = {0, -1, -1, -1, 0, 1, 1, 1};
	queue<mapst> q;
	while(1) {
		cin >> w >> h;
		if(!w&&!h) break;
		ans = 0;
		for(int i=0; i<52; ++i) for(int j=0; j<52; ++j) {
			c[i][j] = 0;
			f[i][j] = 1;
		}
		for(int i=1; i<=h; ++i) for(int j=1; j<=w; ++j) {
			cin >> c[i][j];
			f[i][j] = 1-c[i][j];
		}
		for(int i=1; i<=h; ++i) for(int j=1; j<=w; ++j) {
			if(c[i][j]&&!f[i][j]) {
				mapst m, ms;
				m.x = j; m.y = i;
				q.push(m);
				ans++;
				while(!q.empty()) {
					m = q.front();
					q.pop();
					f[m.y][m.x] = 1;
					for(int k=0; k<8; k++) {
						int nx = m.x + dx[k], ny = m.y + dy[k];
						if(c[ny][nx]&&!f[ny][nx]) {
							ms.x = nx; ms.y = ny;
							q.push(ms);
						}
					}
				};
			}
		}
		cout << ans << endl;
	}
	return 0;
}

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

const int limit=55;
int grid[limit][limit];
int w, h;
int dx[] = {-1, 0, 1, 0, -1, -1, 1, 1}, dy[] = {0, -1, 0, 1, -1, 1, -1, 1};

void dfs(int, int);

int main(){
  while(cin >> w >> h, w!=0 && h!=0){
    //グリッドに情報格納
    for(int i=0; i<h; i++){
      for(int j=0; j<w; j++) cin >> grid[i][j];
    }

    int cnt=0;
    for(int i=0; i<h; i++){
      for(int j=0; j<w; j++){
        if(grid[i][j]==1){
          dfs(i, j);
          cnt++;
        }
      }
    }
    cout << cnt << endl;
  }

  return 0;
}

void dfs(int y, int x){
  if(grid[y][x]==0) return;
  if(y<0 || y>=h || x<0 || x>=w) return;

  grid[y][x] = 0;

  for(int i=0; i<8; i++){
    int ny = y+dy[i], nx = x+dx[i];
    dfs(ny, nx);
  }
}

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

using namespace std;

#define rep(i, n) for (int i = 0; i < int(n); i++)
#define vec vector

int dp[55][55];

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

void dfs(int x, int y)
{
	if (!dp[x][y]) return;
	dp[x][y] = 0;
	rep(i, 8) dfs(x + dx[i], y + dy[i]);
}

int main(void)
{
	while(1) {
		int w, h;
		cin >> w >> h;
		if (!w) break;
		rep(i, h + 2) rep(j, w + 2) dp[i][j] = 0;
		rep(i, h) rep(j, w) {
			cin >> dp[i + 1][j + 1];
		}
		
		int ret = 0;
		rep(i, h) rep(j, w) {
			if (!dp[i + 1][j + 1]) continue;
			ret++;
			dfs(i + 1, j + 1);
		}
		cout << ret << endl;
	}
	return 0;

}

C++: #include <bits/stdc++.h>
#define rep(i, n) for (int i = 0; i < (n); ++i)
using namespace std;
// using ll = long long;
// using P = pair<int, int>;

int m[51][51];
bool check[51][51];

void dfs(int y, int x, int w, int h){
    if(x < 0 || y < 0 || y >= h || x >= w) return;
    if(m[y][x] == 1 && !check[y][x]){
        check[y][x] = true;
        // cout << "[" << y << "," << x << "]" << endl;
        for(int dx = -1; dx <= 1; ++dx){
            for(int dy = -1; dy <= 1; ++ dy){
                dfs(y + dy, x + dx, w, h);
            }
        }
    }
}

int main() {
    int w, h;
    cin >> w >> h;
    
    while(w != 0 && h != 0){
        int res = 0;
        rep(i, 51) rep(j, 51){
            m[i][j] = 0;
            check[i][j] = false;
        }
        rep(i, h) rep(j, w) cin >> m[i][j];
        
        rep(i, h) rep(j, w){
            if(m[i][j] == 1 && !check[i][j]){
                ++res;
                // cout << "start[" << i << "," << j << "]" << endl; 
                dfs(i, j, w, h);
            }   
        }
        
        cout << res << endl;
        cin >> w >> h;
    }
    
    return 0;
}

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

int w,h;
int fd[50][50];

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

void dfs(int x, int y){
	fd[y][x] = 0;
	for(int i=0; i<8; i++){
		int mx = x+dx[i];
		int my = y+dy[i];
		if(0<=mx && mx<w && 0<=my && my<h && fd[my][mx])
			dfs(mx, my);
	}
}

int main(void){
	while(cin >> w >> h, w|h){
		for(int y=0; y<h; y++)
			for(int x=0; x<w; x++)
				cin >> fd[y][x];

		int count=0;
		for(int y=0; y<h; y++)
			for(int x=0; x<w; x++)
				if(fd[y][x]){
					count++;
					dfs(x,y);
				}
		
		cout << count << endl;
	}

	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<n;i++)
#define all(x) (x).begin(),(x).end()
using namespace std;
const int INF=1145141919,MOD=1e9+7;
const long long LINF=8101145141919364364;
const int dx[]={1,1,0,-1,-1,-1,0,1},dy[]={0,-1,-1,-1,0,1,1,1};

int main(){
    int w,h;
    while(cin>>w>>h&&w){
        int c[h][w]; rep(i,h)rep(j,w) cin>>c[i][j];
        int cnt=1;
        for(int i=0;i<h;i++){
            for(int j=0;j<w;j++){
                if(c[i][j]==1){
                    cnt++;
                    queue<pair<int,int>> q;
                    c[i][j]=cnt;
                    q.push({i,j});
                    while(q.size()){
                        pair<int,int> p=q.front(); q.pop();
                        int cy=p.first,cx=p.second;
                        rep(k,8){
                            int ny=cy+dy[k],nx=cx+dx[k];
                            if(0<=ny&&ny<h&&0<=nx&&nx<w&&c[ny][nx]==1){
                                c[ny][nx]=cnt;
                                q.push({ny,nx});
                            }
                        }
                    }
                }
            }
        }
        cout<<cnt-1<<endl;
    }
    return 0;
}