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>
#include <vector>

using namespace std;


int read_map(vector< vector <int> >& map,int &w, int &h){
  cin >> w >>  h;
  if (w == 0 && h == 0){
    return 0;
  }
  map.reserve(h);
  for (int i = 0; i < h ; ++i) map[i].resize(w);
  for (int i = 0; i < h; ++i)
  {
    for (int j = 0; j < w; ++j)
    {
      cin >> map[i][j];
    }
  }
  return 1;
}


bool island_check(vector<vector<int> >& map, int i, int j){
  if (map[i][j] == 1){
    return true;
  }
  return false;
}

void walk_island(vector<vector<int> >& map, int i, int j, int w, int h){
  int start_i, start_j;
  start_i = i;
  start_j = j;
  while (++j < w){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  j = start_j;
  while (--j >= 0){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  while (++i < h){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  while (--i >= 0){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (++i < h && ++j < w){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (--i >= 0 && ++j < w){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  i = start_i;
  j = start_j;
  while (--i >= 0 && --j >= 0){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
  while (++i < h && --j >= 0){
    if (island_check(map, i, j))
    {
      map[i][j] = 2;
      walk_island(map, i, j, w, h);
    }else{
      break;
    }
  }
}

int search_island_num(vector< vector <int> >& map, int w, int h){
  int island_count = 0;
  for (int i = 0; i < h; ++i)
  {
    for (int j = 0; j < w; ++j)
    {
      if(map[i][j] == 1){
        island_count++ ;
        map[i][j] = 2;
        walk_island(map, i, j, w, h);
      }
    }
  }
  return island_count;
}

int main(){
  vector< vector<int> > map;
  int w, h;
  while (read_map(map, w, h) != 0) {
    cout << search_island_num(map, w, h) << endl;
    map.clear();
  }
}

C++: #include <iostream>
#include <vector>
#include <algorithm>
long long w, h;
std::vector<std::vector<int>> c;
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 newx = x + i, newy = y + j;
            if(0 <= newx && newx < h && 0 <= newy && newy < w && c[newx][newy] == 1) dfs(newx, newy);
        }
    }
}
int main(){
    while(1){
        w = 0;
        h = 0;
        std::cin >> w >> h;
        if(w == 0 && h == 0) break;
        std::vector<std::vector<int>> l;
        c = l;
        c.resize(h, std::vector<int> (w));
        for(int i =0 ; i < h; i++){
            for(int j = 0; j < w; j++) std::cin >> c[i][j];
        }
        long long ans = 0;
        for(int i = 0; i < h; i++){
            for(int j = 0; j < w; j++){
                if(c[i][j] == 1) {
                    dfs(i, j);
                    ans++;
                }
            }
        }
        std::cout << ans << std::endl;
    }
}

C++: #include <iostream>

using namespace std;

int W, H;
int field[55][55];

void input(void){
	cin >> W;
	cin >> H;

	for(int i = 0;i < H;i++){
		for(int j = 0;j < W;j++){
			cin >> field[j][i];
		}
	}
}

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, ny = y + dy;
			if(0 <= nx && nx < W && 0 <= ny && ny < H && field[nx][ny] == 1) dfs(nx, ny);
		}
	}

	return ;
}

int main(){
	while(1){
		int res = 0;
		input();
		if(W == 0 && H == 0) break;

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

		cout << res << endl;
	}

	return 0;
}