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++: /* {{{ Shinobu kawaii */
/*
  ______   __        _                  __                 
.' ____ \ [  |      (_)                [  |                
| (___ \_| | |--.   __   _ .--.   .--.  | |.--.   __   _   
 _.____`.  | .-. | [  | [ `.-. |/ .'`\ \| '/'`\ \[  | | |  
| \____) | | | | |  | |  | | | || \__. ||  \__/ | | \_/ |, 
 \______.'[___]|__][___][___||__]'.__.'[__;.__.'  '.__.'_/ 
                                                           
*/
/* }}} */

// #define int long long

/* cpp template {{{ */
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <climits>
#include <iostream>
#include <vector>
#include <string>
#include <sstream>
#include <algorithm>
#include <utility>
#include <set>
#include <map>
#include <stack>
#include <queue>
#include <deque>
#include <functional>
using namespace std;

/* short */
#define pb push_back
#define mp make_pair
#define print(x) cout << x << '\n'
#define Fi first
#define Se second

/* REPmacro */
#define REPS(i, a, n) for (int i = (a); i < (n); i++)
#define REP(i, n) for (int i = 0; i < (n); i++)
#define RREP(i, n) for (int i = 1; i <= (n); i++)
#define DEPS(i, a, n) for (int i = (a); i >= n; i--)
#define DEP(i, n) for (int i = (n); i >= 0; i--)

/* typedef */
typedef long long ll;
typedef unsigned long long ull;
typedef vector<int> vi;
typedef vector<vector<int> > vii;
typedef pair<int, int> pii;

/* const */
const int INF = 999999999;
const int dx[] = {0, 1, 0, -1, 1, -1, 1, -1}, dy[] = {1, 0, -1, 0, 1, -1, -1, 1};

/* func */
inline bool is_uruu(int y) {return (y % 4 == 0 && (y % 100 != 0 || y % 400 == 0));}
inline bool inside(int y, int x, int H, int W) {return (y >= 0 && x >= 0 && y < H && x < W);}

/* }}} */

bool field[56][56];
int w, h;

void dfs(int y, int x)
{
  field[y][x] = false;

  REP(i, 8){
    int nx = x + dx[i], ny = y + dy[i];
    if (!inside(ny, nx, h, w)) continue;
    if (!field[ny][nx]) continue;
    dfs(ny, nx);
  }
}

signed main()
{
  cin.tie(0);
  ios::sync_with_stdio(false);
  
  for (; cin >> w >> h, w || h; ){
    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++;
        }
      }
    }
    print(ans);
  }

  return (0);
}

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

using namespace std;

typedef long long ll;
typedef pair<int,int> pii;
typedef vector<int> VI;
typedef vector<VI> VVI;
const double PI = 3.14159265358979323846;
const double EPS = 1e-12;
const int INF = numeric_limits<int>::max() / 2;
const int NEG_INF = numeric_limits<int>::min() / 2;

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

void dfs(int x,int y){
    tiles[x][y]=0;

    for(int dx=-1;dx<=1;dx++){
      for(int dy=-1;dy<=1;dy++){
        int nx=x+dx,ny=y+dy;

        if(0<=nx && nx<w && 0<=ny && ny<h &&
          tiles[nx][ny] == 1) dfs(nx,ny);
        }
    }
}

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

  while(true){
    for(int i=0;i<51;i++){
      for(int j=0;j<51;j++){
        tiles[i][j]=0;
      }
    }
    int ans=0;
    cin >> w >> h;
    if(w==0) break;
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
        cin >> tiles[j][i];
      }
    }
    for(int i=0;i<h;i++){
      for(int j=0;j<w;j++){
        if(tiles[j][i]==1){
           dfs(j,i);
           ans++;
         }
      }
    }
    cout << ans << endl;
  }
}

C++: #define _USE_MATH_DEFINES
#define _CRT_SECURE_NO_WARNINGS
#include <bits/stdc++.h>
using namespace std;
//
#define int long long
#define ALL(x) (x).begin(), (x).end()
#define UNIQUE(v) (v).erase(unique((v).begin(), (v).end()), (v).end());
#define m0(x) memset((x), 0, sizeof(x))
#define mm(x) memset((x), -1, sizeof(x))
// bit_macro
#define bit(n) (1LL << (n))
#define bitset(a, b) (a) |= (1 << (b))
#define bitunset(a, b) (a) |= ~(1 << (b))
#define bitcheck(a, b) ((a) >> (b)) & 1
#define bitcount(a) __builtin_popcountll((a))
//
typedef long long lint;
typedef pair<int, int> P;
typedef tuple<int, int, int> TP;
typedef vector<int> vec;
typedef vector<vec> mat;
//
const int INF = (int)1e18;
const int MOD = (int)1e9 + 7;
const double EPS = (double)1e-10;
const int dx[] = {-1, 0, 0, 1};
const int dy[] = {0, -1, 1, 0};
//
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); }
//
struct Accelerate_Cin {
  Accelerate_Cin() {
    cin.tie(0);
    ios::sync_with_stdio(0);
    cout << fixed << setprecision(20);
  };
};

int w, h;
int c[60][60];

void dfs(int y, int x) {
  if (c[y][x] == 0) {
    return;
  }

  c[y][x] = 0;

  for (int i = -1; i <= 1; i++) {
    for (int j = -1; j <= 1; j++) {
      if (c[y + i][x + j] == 1) {
        dfs(y + i, x + j);
      }
    }
  }
}

signed main() {
  while (cin >> w >> h, (w != 0 || h != 0)) {
    m0(c);
    for (int i = 1; i <= h; i++) {
      for (int j = 1; j <= w; j++) {
        cin >> c[i][j];
      }
    }

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

    cout << cont << endl;
  }
  return 0;
}