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 <sstream>
#include <string>
#include <vector>
#include <stack>
#include <queue>
#include <deque>
#include <set>
#include <map>
#include <algorithm>
#include <functional>
#include <numeric>
#include <utility>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <complex>
using namespace std;

typedef long long ll;
typedef pair<int,int> P;

#define all(c) (c).begin(),(c).end()
#define pb push_back
#define mp make_pair
#define ERASE(v,i) (v).erase(remove(all(v),i),(v).end())
#define rep(i,n) for(int i=0;i<(int)n;++i)
#define each(it,c) for(typeof((c).begin()) it=(c).begin();it!=(c).end();++it)
#define debug(x) cerr<<#x<<" = "<<(x)<<endl;
#define LINE cerr<<"LINE: "<<__LINE__<<endl;

inline int toInt(string s){int v;istringstream sin(s);sin>>v;return v;}
template<class T> inline string toString(T x){ostringstream sout;sout<<x;return sout.str();}
template<class T> void preview(T a,T b){for(T it=a;it!=b;++it)cerr<<*it<<" ";cerr<<endl;}

const int INF = 100000000;
const double PI = acos(-1.0), EPS = 1e-10;

int field[50][50];
int W, H;

void dfs(int y, int x) {

	queue<P> que;
	que.push(mp(y,x));
	while(!que.empty()) {
		P here = que.front();
		que.pop();
		for(int dy = -1; dy <= 1; dy++) for(int dx = -1; dx <= 1; dx++) {
			int ny = here.first + dy;
			int nx = here.second + dx;
			if(0 <= ny && ny < H && 0 <= nx && nx < W && field[ny][nx] == 1) {
				field[ny][nx] = 0;
				que.push(mp(ny, nx));
			}
		}
	}
}

int main() {
	for(; cin >> W >> H, W || H;) {

		memset(field, 0, sizeof field);
		rep(i,H) rep(j,W) cin >> field[i][j];
		int ans = 0;
		rep(i,H) rep(j,W) if(field[i][j]) {
			dfs(i,j);
			ans++;
		}
		cout << ans << endl;
	}
	return 0;
}

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

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

bool in(int x,int y) {
	return 0<=x&&x<w&&0<=y&&y<h;
}

void dfs(int x,int y) {
	m[x][y]=0;
	for(int i=1;i>=-1;i--) {
		for(int j=1;j>=-1;j--) {
			int nx=x+i,ny=y+j;
			if(in(nx,ny)&&m[nx][ny]) dfs(nx,ny);
		}
	}
}

int main() {
	while(scanf("%d %d",&w,&h),w||h) {
		for(int j=0;j<h;j++) {
			for(int i=0;i<w;i++) {
				scanf("%d",&m[i][j]);
			}
		}
		int count=0;
		for(int j=0;j<h;j++) {
			for(int i=0;i<w;i++) {
				if(m[i][j]) count++,dfs(i,j);
			}
		}
		printf("%d\n",count);
	}
}

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

#define SEA     ( 0)
#define LAND    ( 1)
#define VISITED (-1)

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

int dfs(std::vector<std::vector<int> >& field, const int width, const int height, const int x, const int y) {
  if (field[y][x] == VISITED || field[y][x] == SEA)
    return 0;
  field[y][x] = VISITED;
  for (int i = 0; i < 8; ++i) {
    int cx = x + dx[i], cy = y + dy[i];
    if (cx < 0 || cy < 0 || width <= cx || height <= cy)
      continue;
    dfs(field, width, height, cx, cy);
  }
  return 1;
}

int main(int argc, char const* argv[])
{
  while (true) {
    int w, h;
    std::cin >> w >> h;
    if (w == 0 && h == 0)
      break;
    std::vector<std::pair<int, int> > lands;
    int n_lands = 0;
    std::vector<std::vector<int> > field(h, std::vector<int>(w, 0));
    for (int y = 0; y < h; ++y) {
      for (int x = 0; x < w; ++x) {
        std::cin >> field[y][x];
        if (field[y][x] == LAND) {
          lands.push_back(std::make_pair<int, int>(x, y));
          ++n_lands;
        }
      }
    }
    int ans = 0;
    for (int i = 0; i < n_lands; ++i) {
      ans += dfs(field, w, h, lands[i].first, lands[i].second);
    }
    std::cout << ans << std::endl;
  }
  return 0;
}

C++: #include <bits/stdc++.h>
#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 FORR(i, m, n) for(int i = m;i >= n;i--)
#define SORT(v, n) sort(v, v+n);
#define VSORT(v) sort(v.begin(), v.end());
#define ll long long
#define pb(a) push_back(a)
#define INF 1000000000
using namespace std;
typedef pair<int, int> P;
typedef pair<ll, ll> LP;
typedef pair<int, P> PP;
typedef pair<ll, LP> LPP;

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

int g[50][50];
bool reach[50][50]={0};
int w,h;

void dfs(int x, int y){
 
  reach[x][y] = true;
  
  REP(i,8){
    int nx = x + dx[i], ny = y + dy[i];
    if(0<=nx && nx < h && 0<=ny && ny < w && !reach[nx][ny] && g[nx][ny] == 1) dfs(nx,ny);
  }
  return;
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);

  while(1){
    cin >> w >> h;
    if(!w && !h) return 0;
    
    REP(i,h){
      REP(j,w){
        reach[i][j] = false;
        cin >> g[i][j];
      }
    }
  
    int ans=0;

    REP(i,h){
      REP(j,w){
        if(g[i][j] == 1 && !reach[i][j]){
          dfs(i,j);
          ans++;
        }
      
      }
    }
    cout << ans << endl;
  }
    return 0;
}