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 <stack>

using std::cin;
using std::cout;
using std::endl;

int main(void) {
	int w,h;
	cin >> w;
	cin >> h;

	while (w!=0||h!=0) {
		int count = 0;
		std::stack<int> st_x,st_y;
		int xn,yn;
		int c;
		bool all = false;
		std::vector< std::vector<bool> > island(h+2, std::vector<bool>(w+2));
		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) {
					island[i][j] = false;
				} else {
					cin >> c;
					if (c==1) {
						island[i][j] = true;
					} else {
						island[i][j] = false;
					}
				}
			}
		}

		while (!all) {
			all = true;
			for (int i = 1; i < h+1; i++) {
				for (int j = 1; j < w+1; j++) {
					if (island[i][j]) {
						xn = i;
						yn = j;
						all = false;
					}
				}
			}
			if (!all) {
				st_x.push(xn);
				st_y.push(yn);
				if (island[xn][yn]) {
					island[xn][yn] = false;
					count++;

					while (!st_x.empty()) {
						xn = st_x.top();
						yn = st_y.top();
						st_x.pop();
						st_y.pop();
						if (island[xn+1][yn]) {
							st_x.push(xn+1);
							st_y.push(yn);
							island[xn+1][yn] = false;
						}
						if (island[xn-1][yn]) {
							st_x.push(xn-1);
							st_y.push(yn);
							island[xn-1][yn] = false;
						}
						if (island[xn+1][yn+1]) {
							st_x.push(xn+1);
							st_y.push(yn+1);
							island[xn+1][yn+1] = false;
						}
						if (island[xn+1][yn-1]) {
							st_x.push(xn+1);
							st_y.push(yn-1);
							island[xn+1][yn-1] = false;
						}
						if (island[xn-1][yn+1]) {
							st_x.push(xn-1);
							st_y.push(yn+1);
							island[xn-1][yn+1] = false;
						}
						if (island[xn-1][yn-1]) {
							st_x.push(xn-1);
							st_y.push(yn-1);
							island[xn-1][yn-1] = false;
						}
						if (island[xn][yn+1]) {
							st_x.push(xn);
							st_y.push(yn+1);
							island[xn][yn+1] = false;
						}
						if (island[xn][yn-1]) {
							st_x.push(xn);
							st_y.push(yn-1);
							island[xn][yn-1] = false;
						}
					}
				}
			}
		}
		cout << count << endl;

		cin >> w;
		cin >> h;
	}	
		return 0;
}

C++: #include <bits/stdc++.h>
#define int long long
#define double long double
#define INF 1e18
using namespace std;

int W, H;
int c[1000][1000];

void dfs(int x, int y) {
  int moveX[3] = {0,-1,1};
  int moveY[3] = {0,-1,1};
  c[x][y] = 0;
  for(int i = 0; i < 3; i++) {
    for(int j = 0; j < 3; j++) {
      int nx=x+moveX[i], ny=y+moveY[j];
      if(nx<0||ny<0) continue;
      if(c[nx][ny] == 1) dfs(nx,ny);
    }
  }
}

signed main() {
  cin>>W>>H;
  while (W+H!=0) {
    // i = y, j = x
    for(int i=0;i<1000;i++)for(int j=0;j<1000;j++)c[i][j]=0;
    for(int i=0;i<H;i++){
      for(int j= 0;j<W;j++){
        cin>>c[i][j];
      }
    }
    
    int 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++;
        }
      }
    }
    cout << ans << endl;
    cin >> W >> H;
  }
}

C++: #include <iostream>
#include <iomanip>
#include <sstream>
#include <vector>
#include <array>
#include <list>
#include <stack>
#include <queue>
#include <set>
#include <map>
#include <unordered_set>
#include <unordered_map>
#include <string>
#include <algorithm>
#include <numeric>
#include <utility>
#include <cstdlib>
#include <ctime>
#include <cstdint>
#include <cmath>

#define FOR(i,k,n)  for(int i = (k);i < (n);++i)
#define REP(i,n)    FOR(i,0,n)
#define EACH(i,x)   for(auto & i : x)
#define ALL(x)      begin(x),end(x)

using namespace std;

typedef vector<int> vecint;

int root(int i,vecint& p){
  if(p[i] != i+1)
    p[i] = root(p[i]-1,p);
  return p[i];
}
void join(int i,int j,vecint& p){
  p[root(i,p)-1] = root(j,p);
}

int main()
{
  while(true){
    int w,h;cin>>w>>h;
    if(!(w||h))break;
    vector<vecint> m(h+2,vecint(w+2));
    REP(i,h)REP(j,w)cin>>m[i+1][j+1];
    int n=(w+2)*(h+2);
    vecint p(n);
    REP(i,n)p[i]=i+1;
    REP(i,h)REP(j,w){
      int di[8] = {1,1,1,0,-1,-1,-1,0};
      int dj[8] = {1,0,-1,-1,-1,0,1,1};
      REP(k,8){
        int ni=i+di[k];
        int nj=j+dj[k];
        if (m[i+1][j+1] && m[ni+1][nj+1]){
          int ijn = (i+1)*(w+2)+(j+1);
          int nijn = (ni+1)*(w+2)+(nj+1);
          join(ijn,nijn,p);
        }
      }
    }
    set<int> s;
    REP(i,h)REP(j,w){
      if(m[i+1][j+1]){
        int ijn = (i+1)*(w+2)+(j+1);
        s.insert(root(ijn,p));
      }
    }
    cout<<s.size()<<endl;
  }
  return 0;
}