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>
#include <queue>

using namespace std;

int main(void) {
	int w,h;
	while(cin >> w >> h && w && h) {
		vector< vector<int> > data(w+2,vector<int>(h+2));
		vector< vector<bool> > check(w+2,vector<bool>(h+2,false));
		queue<int> sx,sy;
		for (int i = 0; i < h + 2; ++i) {
			for (int j = 0; j < w + 2; ++j) {
				if (i == 0 || i == h+1 || j == 0 || j == w+1) {
					data[i][j] = 0;
				}
				else {
					cin >> data[i][j];
					if (data[i][j] == 1) {
						sx.push(j);
						sy.push(i);
					}
				}
			}
		}

		int nx,ny;
		int count = 0;
		queue<int> fx,fy;
		while(!sx.empty()) {
			nx = sx.front();
			ny = sy.front();
			sx.pop();
			sy.pop();
			if (!check[ny][nx]) {
				check[ny][nx] = true;
				fx.push(nx);
				fy.push(ny);
				++count;
			}
			while (!fx.empty()) {
				nx = fx.front();
				ny = fy.front();
				fx.pop();
				fy.pop();
				//cout << ny << " " << nx << endl;
				if (!check[ny+1][nx] && data[ny+1][nx] == 1) {
					check[ny+1][nx] = true;
					fx.push(nx);
					fy.push(ny+1);
				}
				if (!check[ny-1][nx] && data[ny-1][nx] == 1) {
					check[ny-1][nx] = true;
					fx.push(nx);
					fy.push(ny-1);
				}
				if (!check[ny+1][nx+1] && data[ny+1][nx+1] == 1) {
					check[ny+1][nx+1] = true;
					fx.push(nx+1);
					fy.push(ny+1);
				}
				if (!check[ny+1][nx-1] && data[ny+1][nx-1] == 1) {
					check[ny+1][nx-1] = true;
					fx.push(nx-1);
					fy.push(ny+1);
				}
				if (!check[ny-1][nx-1] && data[ny-1][nx-1] == 1) {
					check[ny-1][nx-1] = true;
					fx.push(nx-1);
					fy.push(ny-1);
				}
				if (!check[ny-1][nx+1] && data[ny-1][nx+1] == 1) {
					check[ny-1][nx+1] = true;
					fx.push(nx+1);
					fy.push(ny-1);
				}
				if (!check[ny][nx+1] && data[ny][nx+1] == 1) {
					check[ny][nx+1] = true;
					fx.push(nx+1);
					fy.push(ny);
				}
				if (!check[ny][nx-1] && data[ny][nx-1] == 1) {
					check[ny][nx-1] = true;
					fx.push(nx-1);
					fy.push(ny);
				}
			}
		}
		cout << count << endl;
	}
	return 0;
}

C++: #include <bits/stdc++.h>
#define rep(i, a, n) for(int i = a; i < n; i++)
#define repb(i, a, b) for(int i = a; i >= b; i--)
#define all(a) a.begin(), a.end()
#define int long long
using namespace std;

int w, h;
char c[51][51];
bool f[51][51];
int ans = 0;


bool contain(int y, int x){
    return (0 <= y && y < h && 0 <= x && x < w);
}

void dfs(int y, int x){
    f[y][x] = true;
    if(c[y][x] == '0') return;
    rep(i, 0, 3){
        rep(j, 0, 3){
            int ny = y + i - 1;
            int nx = x + j - 1;
            if(contain(ny, nx) && f[ny][nx] == false){
                dfs(ny, nx);
            }
        }
    }
    return;
}

signed main(){
    while(cin >> w >> h){
        if(w + h == 0) break;
        rep(i, 0, h){
            rep(j, 0, w){
                cin >> c[i][j];
            }
        }
        rep(i, 0 ,51){
            rep(j, 0, 51){
                f[i][j] = false;
            }
        }
        // cout << -1 << endl;
        ans = 0;
        rep(i, 0, h){
            rep(j, 0 ,w){
                if(c[i][j] == '1' && f[i][j] == false){
                    // cout << i << ' ' << j << endl;
                    dfs(i, j);
                    ans++;
                }
            }
        }
        cout << ans << endl;
    }

}

C++: #include<iostream>
#include<vector>
#include<algorithm>
#include<cmath>
#include<ctime>

using namespace std;
using ll = long long;

int dir[2][8] = {{-1, -1, -1, 0, 1, 1, 1, 0}, {-1, 0, 1, -1, -1, 0, 1, 1}};

void dfs(int i, int j, vector<vector<int>>& used, vector<vector<int>>& color){
  used[i][j] = 1;
  for(int d = 0; d < 8; d++){
    if(i + dir[0][d] >= 0 && i + dir[0][d] < used.size() && j + dir[1][d] >= 0 && j + dir[1][d] < used[0].size()){
      if(!used[i+dir[0][d]][j+dir[1][d]] && color[i+dir[0][d]][j+dir[1][d]]){
        dfs(i + dir[0][d], j + dir[1][d], used, color);
      }
    }
  }
}

int main(){
  cin.tie(0);
  ios::sync_with_stdio(false);
  int ti = clock();
  // start-----------------------------------------------
  int w, h;
  while(cin >> w >> h && w){
    vector<vector<int> > used(h, vector<int>(w, 0));
    vector<vector<int> > color(h, vector<int>(w, 0));
    int ans = 0;
    for(int i = 0; i < h; i++){
      for(int j = 0; j < w; j++){
        cin >> color[i][j];
      }
    }
    for(int i = 0; i < h; i++){
      for(int j = 0; j < w; j++){
        if(!used[i][j] && color[i][j]) ans++, dfs(i, j, used, color);
      }
    }
    cout << ans << endl;
  }

  // end-----------------------------------------------
  // cerr << 1.0 * (clock() - ti) / CLOCKS_PER_SEC << endl;
}