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;
int c[51][51];
bool used[51][51];

void dfs(int x,int y) {
    used[x][y]=1;
    for(int dx=-1; dx<=1; ++dx) {
        for(int dy=-1; dy<=1; ++dy) {
            int xx=x+dx;
            int yy=y+dy;
            if(x+dx < 0 || x+dx >=h) continue;
            if(y+dy < 0 || y+dy >=w) continue;
            if(used[xx][yy] || c[xx][yy]==0) continue;
            dfs(xx,yy);
        }
    }
}

int main() {
    while(true) {
        int ans=0;
        cin>>w>>h;
        if(!w) return 0;
        for(int i=0; i<h; ++i) {
            for(int j=0; j<w; ++j) {
                cin>>c[i][j];
                used[i][j]=0;
            }
        }
        for(int i=0; i<h; ++i) {
            for(int j=0; j<w; ++j) {
                if(used[i][j] || c[i][j]==0) continue;
                //cerr<<i<<" "<<j<<endl;
                dfs(i,j);
                ans++;
            }
        }
        cout<<ans<<endl;
    }
}

C++: #include <iostream>
#include <string>
#include <cstring>
#include <fstream>
#include <random>
#include <cmath>
#include <iomanip>
#include <climits>
#include <cstdlib>
#include <algorithm>
#include <vector>
#include <map>
#include <deque>
#include <map>
#include <set>
#include <queue>
#include <stack>
#include <list>
#include <unordered_map>
#include <bitset>
#include <sstream>
#include <new>
#include <typeinfo>
#include <iterator>

typedef long long ll;
typedef unsigned long long ull;
constexpr ll mop = 1000000007;
constexpr ll mop2 = 998244353;

using namespace std;

void dfs(const ll& x, const ll& y, vector<vector<bool>>& grid, const ll& h, const ll & w) {
	grid[x][y] = false;
	for (ll dx = -1; dx <= 1; dx++) {
		for (ll dy = -1; dy <= 1; dy++) {
			ll nextx = x + dx;
			ll nexty = y + dy;
			if (0 <= nextx && nextx < h && 0 <= nexty && nexty < w && grid[nextx][nexty] == true) {
				dfs(nextx, nexty, grid, h, w);
			}
		}
	}
}

int main() {
	while (true) {
		ll w, h;
		cin >> w >> h;
		if (w == 0 && h == 0) {
			break;
		}
		vector<vector<bool>> grid(h);
		for (ll i = 0; i < h; i++) {
			grid[i].resize(w);
			for (ll j = 0; j < w; j++) {
				ll tmp;
				cin >> tmp;
				grid[i][j] = (tmp == 1 ? true : false);
			}
		}
		ll ans = 0;
		for (ll i = 0; i < h; i++) {
			for (ll j = 0; j < w; j++) {
				if (grid[i][j] == true) {
					ans++;
					dfs(i, j, grid, h, w);
				}
			}
		}
		cout << ans << endl;
	}
}

C++: #include <iostream>
#include <string>
#include <utility>
#include <stack>
#include <vector>
#include <queue>
#include <algorithm>
#include <map>
#include <climits>
#include <set>
#include <numeric>
#include <iomanip>
#include <cmath>
#include <cstring>
using namespace std;
int grid[50][50];
bool used[50][50];
int move_h[8] = {-1, 1, 0, 0, -1, 1, -1, 1};
int move_w[8] = {0, 0, -1, 1, 1, -1, -1, 1};

void dfs(int cur_h, int cur_w, int h, int w){
  used[cur_h][cur_w] = true;
  for(int i = 0; i < 8; i++){
    int next_h = cur_h + move_h[i];
    int next_w = cur_w + move_w[i];

    if(0 <= next_h && next_h < h && 0 <= next_w && next_w < w 
        && !used[next_h][next_w] && grid[next_h][next_w] == 1){
      dfs(next_h, next_w, h, w);
    }
  }
}
int main(){
  while(true){
    int w;
    int h;
    cin >> w >> h;
    if(w == 0 && h == 0){
      break;
    }
    for(int i = 0; i < h; i++){
      for(int j = 0; j < w; j++){
        cin >> grid[i][j];
        used[i][j] = false;
      }
    }

    int ans = 0;
    for(int i = 0; i < h; i++){
      for(int j = 0; j < w; j++){
        if(!used[i][j] && grid[i][j] == 1){
          ans ++;
          dfs(i, j, h, w);
        }
      }
    }
    cout << ans << endl;
  }
  return 0;
}

C++: #include<iostream>
using namespace std;
void dfs(int,int);
int box[51][51];
int main(){
  int w,h,i,I,a;
  while(1){
    a=0;
    cin>>w>>h;
    if(w==0&&h==0) break;
    for(i=0;i<=h+1;i++){
      for(I=0;I<=w+1;I++){
	box[i][I]==0;
      }
    }
    for(i=1;i<=h;i++){
      for(I=1;I<=w;I++){
	cin>>box[i][I];
      }
    }
    for(i=1;i<=h;i++){
      for(I=1;I<=w;I++){
	if(box[i][I]==1){
	  dfs(i,I);
	  a++;
	}
      }
    }
    cout<<a<<endl;
  }
  return 0;
}
  void dfs(int i,int I){
  if(box[i][I]==0) return;
  box[i][I]=0;
  dfs(i,I+1);
  dfs(i+1,I+1);
  dfs(i+1,I);
  dfs(i+1,I-1);
  dfs(i,I-1);
  dfs(i-1,I-1);
  dfs(i-1,I);
  dfs(i-1,I+1);
  }