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 <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <ctime>
#include <cstring>
#include <functional>
#include <iostream>
#include <iomanip>
#include <limits>
#include <map>
#include <queue>
#include <set>
#include <stack>
#include <string>
#include <regex>
#include <vector>

#define fix(n)          cout<<fixed<<setprecision(n)
#define rep(i,n)        for (int i = 0; i < (n); ++i)
#define all(a)          (a).begin(), (a).end()
#define sort(a)         sort(all(a))
#define uniq(a)         sort(a);(a).erase(unique(all(a), (a).end())
#define reverse(a)      reverse(all(a))
#define ctos(c)         string(1, (c))
#define out(d)          cout << (d)
#define outl(d)         std::cout<<(d)<<"\n"
#define YES()           cout << "YES" << endl
#define NO()            cout << "NO" << endl
#define Yes()           cout << "Yes" << endl
#define No()            cout << "No" << endl
#define ceil(x, y)      ((x + y - 1) / (y))
#define debug(x)        cerr << #x << ": " << (x) << '\n'
#define debug2(x, y)    cerr << #x << ": " << (x) << ", " << #y << ": " << (y) << '\n'
#define debug3(x, y, z) cerr << #x << ": " << (x) << ", " << #y << ": " << (y) << ", " << #z << ": " << (z) << '\n'
#define dbg(v)          for (size_t _ = 0; _ < v.size(); ++_){ cerr << #v << "[" << _ << "] : " << v[_] << '\n'; }
#define pb              push_back
#define fst             first
#define int             long long
#define INF             __LONG_LONG_MAX__

using namespace std;
using ll = long long;
using ld = long double;
using P = pair<ll,ll>;

const ll MOD = 1000000007; // 10^9 + 7
const int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
const int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};

void solve2(ll w, ll h) {
  vector<vector<int>> grid(h);
  rep(i, h) {
    grid[i].resize(w);
    rep(j, w) cin >> grid[i][j];
  }

  ll ans = 0;
  for (int i = 0; i < h; i++) {
    for (int j = 0; j < w; j++) {
      if (grid[i][j] != 1) continue;

      queue<ll> qx, qy;
      qx.push(j); qy.push(i); grid[i][j] = -1;
      while (!qx.empty()) {
        ll x = qx.front(); qx.pop();
        ll y = qy.front(); qy.pop();

        for (int k = 0; k < 8; k++) {
          ll nx = x + dx[k];
          ll ny = y + dy[k];

          if (nx >= 0 && nx < w && ny >= 0 && ny < h && grid[ny][nx] == 1) {
            grid[ny][nx] = -1;
            qx.push(nx);
            qy.push(ny);
          }
        }
      }

      ans++;
    }
  }
  outl(ans);
}

void solve() {
  while (true) {
    ll w, h; cin >> w >> h;
    if (w == 0 && h == 0) break;
    solve2(w, h);
  }
}

signed main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  srand((unsigned)time(NULL));
  fix(12);

  solve();
}

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

using namespace std;
const int dx[] = {-1, -1, -1, 0, 0, 1, 1, 1};
const int dy[] = {-1, 0, 1, -1, 1, -1, 0, 1};

int main(void) {
	int w,h;
	while(cin >> w >> h && w && h) {
		vector< vector<int> > data(h+2,vector<int>(w+2,0));
		for (int i = 1; i <= h; ++i) {
			for (int j = 1; j <= w; ++j) {
				cin >> data[i][j];
			}
		}

		int nx,ny;
		int count = 0;
		for (int i = 1; i <= h; ++i) {
			for (int j = 1; j <= w; ++j) {
				if (data[i][j] == 1) {
					nx = j;
					ny = i;
					data[i][j] = 0;
					queue<int> fx,fy;
					fx.push(nx);
					fy.push(ny);
					++count;

					while (!fx.empty()) {
						nx = fx.front();
						ny = fy.front();
						fx.pop();
						fy.pop();
						for (int d = 0; d < 8; ++d) {
							if (data[ny+dy[d]][nx+dx[d]] == 1) {
								fx.push(nx+dx[d]);
								fy.push(ny+dy[d]);
								data[ny+dy[d]][nx+dx[d]] = 0;
							}
						}
					}
				}
			}
		}
		cout << count << endl;
	}
	return 0;
}

C++: #include <iostream>

using namespace std;
int c[51][51];
int w ,h;

bool input(){
	cin >> h >> w;
	if(w==0) return false;
	for(int i = 0;i <51;i++){
		for(int j = 0;j <51 ;j++){
			c[i][j] = 2;
		}
	}

	for(int i = 0;i < w ;i++){
		for(int j = 0; j < h ;j++){
			cin >> c[i][j];
//			cout <<c[i][j];
		}
	}
	return true;
}

void dfs(int x,int y){
	c[x][y] = 0;
	for(int i = -1; i <=1 ;i++){
		for(int j = -1; j <=1 ;j++){
			int nx = x + i;
			int ny = y + j;
//			cout <<nx << ' ' << ny << endl;
			if(0 <= nx && nx < w && 0 <= ny && ny < h && c[nx][ny] == 1)dfs(nx,ny);
		}
	}
}

void solve(){
	int res = 0;
/*	for(int i=0;i < w ;i++){
		for (int j=0;j < h;j++){
			cout <<c[i][j];
		}
		cout <<endl;
	}
*/
	for(int i=0; i < w;i++){
		for(int  j=0;j < h;j++){
			if(c[i][j] ==1){
//				cout << i << ' ' << j << endl;
				res++;
				dfs(i,j);
			}
		}
	}
	cout << res << endl;

/*	for(int i=0;i < w ;i++){
		for (int j=0;j<h;j++){
			cout <<c[i][j];
		}
		cout <<endl;
	}
	*/
}

int main(){
	while(input())solve();
}

C++: #include <iostream> // C++の入出力
#include <stdio.h> // C の入出力
#include <algorithm> // sort などのアルゴリズム
#include <string.h> // C の文字列用
#include <ctype.h> // C の文字種用
#include <string> // C++の文字列
#include <math.h>
#include <sstream>
using namespace std;
bool fel[100][100];
int w,h;
void dif(int x,int y);
int main(void){
    while(true){
        cin>>w>>h;
        if(w+h==0)break;
        for(int s=0;s<h;s++){
            for(int i=0;i<w;i++){
                cin>>fel[s][i];
            }
        }
        int cnt=0;
        for(int s=0;s<h;s++){
            for(int i=0;i<w;i++){
                if(fel[s][i]){
                    dif(i,s);
                    cnt++;
                }
            }
        }
        cout<<cnt<<endl;
    }
    return 0;
}
void dif(int x,int y){
    fel[y][x]=0;
    for(int s=-1;s<=1;s++){
        for(int i=-1;i<=1;i++){
            int nx=x+i,ny=y+s;
            if(nx>=0&&nx<w&&ny>=0&&ny<h&&fel[ny][nx])dif(nx, ny);
        }
    }
    return;
}