Go: package main

import (
	"bufio"
	"fmt"
	"io"
	"math"
	"os"
	"strconv"
)

var (
	readString func() string
	readBytes  func() []byte
	stdout     *bufio.Writer
)

func init() {
	readString, readBytes = newReadString(os.Stdin)
	stdout = bufio.NewWriter(os.Stdout)
}

func newReadString(ior io.Reader) (func() string, func() []byte) {
	r := bufio.NewScanner(ior)
	r.Buffer(make([]byte, 1024), math.MaxInt32)
	r.Split(bufio.ScanWords)

	f1 := func() string {
		if !r.Scan() {
			panic("Scan failed")
		}
		return r.Text()
	}
	f2 := func() []byte {
		return []byte(f1())
	}
	return f1, f2
}

func readInt() int {
	return int(readInt64())
}

func readInt64() int64 {
	i, err := strconv.ParseInt(readString(), 10, 64)
	if err != nil {
		panic(err.Error())
	}
	return i
}

func readFloat64() float64 {
	f, err := strconv.ParseFloat(readString(), 64)
	if err != nil {
		panic(err.Error())
	}
	return f
}

func printf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(stdout, f, args...)
}

func println(args ...interface{}) (int, error) {
	return fmt.Fprintln(stdout, args...)
}

func eprintln(args ...interface{}) (int, error) {
	return fmt.Fprintln(os.Stderr, args...)
}

func eprintf(f string, args ...interface{}) (int, error) {
	return fmt.Fprintf(os.Stderr, f, args...)
}

func min(a, b int) int {
	if a < b {
		return a
	}
	return b
}

func min64(a, b int64) int64 {
	if a < b {
		return a
	}
	return b
}

func max(a, b int) int {
	if a < b {
		return b
	}
	return a
}

func max64(a, b int64) int64 {
	if a < b {
		return b
	}
	return a
}

func abs(a int) int {
	if a < 0 {
		return -a
	}
	return a
}

func abs64(a int64) int64 {
	if a < 0 {
		return -a
	}
	return a
}

func gcd(a, b int) int {
	if b == 0 {
		return a
	}
	return gcd(b, a%b)
}

func gcd64(a, b int64) int64 {
	if b == 0 {
		return a
	}
	return gcd64(b, a%b)
}

// readString() string
// readInt() int
// readInt64() int64
// readFloat64() float64

// -----------------------------------------------------------------------------

func main() {
	defer stdout.Flush()

	for {
		ans, ok := solve()
		if !ok {
			break
		}
		println(ans)
	}

}

func solve() (int, bool) {
	w := readInt()
	h := readInt()
	if w == 0 && h == 0 {
		return 0, false
	}

	c := make([][]int, h+2)
	c[0] = make([]int, w+2)
	c[h+1] = make([]int, w+2)
	for i := 1; i-1 < h; i++ {
		c[i] = make([]int, w+2)
		for j := 1; j-1 < w; j++ {
			c[i][j] = readInt()
		}
	}

	var ans int
	for i := 1; i-1 < h; i++ {
		for j := 1; j-1 < w; j++ {
			if 0 < c[i][j] {
				ans++
				dfs(c, i, j)
			}
		}
	}
	return ans, true
}

func dfs(c [][]int, y, x int) {
	c[y][x] = 0
	dx := []int{-1, 0, 1, -1, 1, -1, 0, 1}
	dy := []int{-1, -1, -1, 0, 0, 1, 1, 1}
	for i := range dx {
		nx := x + dx[i]
		ny := y + dy[i]
		if 0 < c[ny][nx] {
			dfs(c, ny, nx)
		}
	}
}

// -----------------------------------------------------------------------------

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

int islands=0;
int w,h;
int field[50][50];
void bfs(int, int);

int main(){

  while(cin>>w>>h&&w!=0&&h!=0){

    for(int i=0;i<51;i++){
      for(int j=0;j<51;j++){
        field[i][j] = -1;
      }
    }

    for(int j=0;j<h;j++){
      for(int i=0;i<w;i++){
        cin >> field[i][j];
        //        cout << field[i][j] << " ";
      }
      //    cout << endl;
    }
    // cout << endl;
    int ans=0; 

    for(int j=0;j<h;j++){
      for(int i=0;i<w;i++){
        if(field[i][j]==1){
          field[i][j]=0;
          bfs(i,j);
          ans++;
        }
      }
    }
    /*   if(w==5&&h==4){
         for(int i=0;i<w;i++){
         for(int j=0;j<h;j++){
         cout << field[i][j] << " ";
         }
         cout << endl;
         }
         }*/
    cout << ans << endl;
  }

  return 0;
}

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

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

#define MAX 51

bool field[MAX][MAX];
int cnt;
int H, W;

void dfs(int x, int y){
  field[x][y] = 0;
  
  for(int dx = -1 ; dx <= 1 ; dx++){
    for(int dy = -1 ; dy <= 1 ; dy++){
      int nx = x + dx;
      int ny = y + dy;
      if(0 <= nx && nx < H && 0 <= ny && ny < W && field[nx][ny] == 1) dfs(nx, ny);
    }
  }
}

int main(){
  while(cin >> W >> H){
    cnt = 0;
    if(W == 0 && H == 0) break;
    for(int i = 0 ; i < H ; i++){
      for(int j = 0 ; j < W ; j++){
	cin >> field[i][j];
      }
    }

    for(int i = 0 ; i < H ; i++){
      for(int j = 0 ; j < W ; j++){
	if(field[i][j] == 1){
	  dfs(i, j);
	  cnt++;
	}
      }
    }
    cout << cnt << endl;
  }
  return 0;
}

C++: #include<bits/stdc++.h>
using namespace std;

typedef pair<int, int> P;
int w,h;

void dfs(int x, int y, vector<vector<bool>> &maze){
    queue<P> q;
    q.push({x, y});
    maze[x][y] = false;
    while(q.size() > 0){
        int nx = q.front().first;
        int ny = q.front().second;
        q.pop();
        for (int i = -1; i <= 1; i++){
            for (int j = -1; j <= 1; j++){
                if (0 <= nx+i && nx+i < h && 0 <= ny+j && ny+j < w && maze[nx+i][ny+j]){
                    maze[nx+i][ny+j] = false;
                    q.push({nx+i, ny+j});
                }
            }
        }
    }
}

int main(){
    int x;
    int ans;
    while(1){
        cin >> w >> h;
        if (w == 0 || h == 0) break;
        vector<vector<bool>> maze(h, vector<bool>(w));
        for (int i = 0; i < h; i++){
            for (int j = 0; j < w; j++){
                cin >> x;
                maze[i][j] = x;
            }
        }
        
        ans = 0;
        for (int i = 0; i < h; i++){
            for (int j = 0; j < w; j++){
                if (maze[i][j]){
                    dfs(i, j, maze);
                    ans++;
                }
            }
        }
        cout << ans << endl;
    }
}

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

using namespace std;


#define FOR(i,a,b) for (int i=(a);i<(b);i++)
#define RFOR(i,a,b) for (int i=(b)-1;i>=(a);i--)
#define REP(i,n) for (int i=0;i<(n);i++)
#define RREP(i,n) for (int i=(n)-1;i>=0;i--)

int h,w;

int c[52][52];

int cnt;
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 i,int j);



int main(){


	while(1){
		cin >> w >> ;

		if(h==0 && w == 0){
			break;
		}

		cnt=0;

		REP(i,h){
			REP(j,w){


				cin >> c[i][j] ;

			}
		}

		REP(i,h){
			REP(j,w){

				//cnt++??????????????\???????????????????????\???????????????
				if(c[i][j] == 1){
					cnt++;
					dfs(j,i);
				}
			}
		}

		cout << cnt << endl;
	}
	return 0;
}

void dfs(int i,int j){

	if(c[j][i] == 1){

		c[j][i] = 0;
		REP(k,8){
			//w???<=???????????£??????????????????
			if(0 <= i+dx[k] && i+dx[k] < w && 0 <= j+dy[k] && j+dy[k] < h){

				dfs(i+dx[k],j+dy[k]);
			}
		}
	}
}