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 w, h, cnt;
int island[50][50];
int dx[] = {1, 1, 0, -1, -1, -1, 0, 1};
int dy[] = {0, 1, 1, 1, 0, -1, -1, -1};

bool check(int nx, int ny){

  if(nx < 0 || w <= ny || ny < 0 || h < ny)return false;
  else return true;

}

void dfs(int sy, int sx){

  island[sy][sx] = 0;

  for(int i = 0 ; i < 8 ; i++){
    int nx = sx + dx[i];
    int ny = sy + dy[i];
    if(!check(nx, ny)) continue;
    if(island[ny][nx]) dfs(ny, nx);
  }
}

int main(void){

  while(cin >> w >> h, w + h){

    for(int i = 0 ; i < h ; i++)
      for(int j = 0 ; j < w ; j++)
	cin >> island[i][j];

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

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

using namespace std;
typedef vector<vector<int> > field;

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

void erase(field &f, int y, int x)
{
    f[y][x] = 0;
    for(int i=0; i<8; i++)
    {
        if(f[y+dy[i]][x+dx[i]]) erase(f, y+dy[i], x+dx[i]);
    }
}

int main()
{
    int w, h;
    while(cin >> w >> h, w|h)
    {
        field f(h+2, vector<int>(w+2, 0));
        for(int y=1; y<=h; y++)
        {
            for(int x=1; x<=w; x++)
            {
                int c;
                cin >> c;
                f[y][x] = c;
            }
        }
        int ct = 0;
        for(int y=1; y<=h; y++)
        {
            for(int x=1; x<=w; x++)
            {
                if(f[y][x])
                {
                    ct++;
                    erase(f, y, x);
                }
            }
        }
        cout << ct << endl;
    }
}

C++: #include <bits/stdc++.h>
using namespace std;
int hx[8] = {0, 0, 1, -1, 1, 1, -1, -1};
int hy[8] = {1, -1, 0, 0, 1, -1, 1, -1};
vector<vector<int>> mp;
vector<vector<bool>> used;
int w, h;

void dfs(int i, int j) {
  if (used[i][j])
    return;
  used[i][j] = true;
  for (int k = 0; k < 8; k++) {
    int ni = i + hx[k], nj = j + hy[k];
    if (ni >= h || ni < 0 || nj >= w || nj < 0)
      continue;
    if (used[ni][nj] || mp[ni][nj] == 0)
      continue;
    dfs(ni, nj);
  }
}

int main() {
  while (true) {
    cin >> w >> h;
    if (w == 0)
      break;
    mp = vector<vector<int>>(h, vector<int>(w));
    for (int i = 0; i < h; i++)
      for (int j = 0; j < w; j++)
        cin >> mp[i][j];
    used = vector<vector<bool>>(h, vector<bool>(w));
    int ans = 0;
    for (int i = 0; i < h; i++) {
      for (int j = 0; j < w; j++) {
        if (used[i][j])
          continue;
        if (mp[i][j] == 0)
          continue;
        dfs(i, j);
        ans++;
      }
    }
    cout << ans << endl;
  }
}

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

vector<int> route;
#define P 50
#define Q 50
char a[P+2][Q+2];


void search(int place1,int place2){
    a[place1][place2] = '0';
    if(a[place1][place2-1] == '1'){//左
        route.push_back(1);
        search(place1,place2-1);
    }
    else if(a[place1+1][place2] == '1'){//下
        route.push_back(2);
        search(place1+1,place2);
    }
    else if(a[place1][place2+1] == '1'){//右
        route.push_back(3);
        search(place1,place2+1);
    }
    else if(a[place1-1][place2] == '1'){//上
        route.push_back(4);
        search(place1-1,place2);
    }
    else if(a[place1+1][place2-1] == '1'){//左下
        route.push_back(5);
        search(place1+1,place2-1);
    }
    else if(a[place1+1][place2+1] == '1'){//右下
        route.push_back(6);
        search(place1,place2+1);
    }
    else if(a[place1-1][place2+1] == '1'){//右上
        route.push_back(7);
        search(place1-1,place2);
    }
    else if(a[place1-1][place2-1] == '1'){//左上
        route.push_back(8);
        search(place1-1,place2);
    }
    else{
        int bk = route.back();
        route.pop_back();//戻る
        if(bk == 0) return;
        else if(bk == 1)search(place1,place2+1);
        else if(bk == 2)search(place1-1,place2);
        else if(bk == 3)search(place1,place2-1);
        else if(bk == 4)search(place1+1,place2);
        else if(bk == 5)search(place1-1,place2+1);
        else if(bk == 6)search(place1-1,place2-1);
        else if(bk == 7)search(place1+1,place2-1);
        else if(bk == 8)search(place1+1,place2+1);
    }
}

int main(void){
    int ct;
    int x,y;
    while(1){
        ct = 0;
        cin >> y >> x;
        if(x == 0 & y == 0) break;
        for(int i = 0;i < x+2;i++){
            for(int j = 0;j < y+2;j++){
                if(i == 0||j == 0||i == x+1||j == y+1)a[i][j] = '0';
                else cin >> a[i][j];
                
            }
            
        }
        for(int i = 1;i < x+1;i++){
            for(int j = 1;j < y+1;j++){
                if(a[i][j] == '1'){
                    route.push_back(0);
                    search(i,j);
                    ct++;
                }
            }
        }
        cout << ct << endl;
    }
    return 0;
}