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 <bits/stdc++.h>
 
using namespace std;

int visited[50][50];
const int offset[8][2] = {
    {1,0},{1,1},{0,1},{-1,1},{-1,0},{-1,-1},{0,-1},{1,-1}
};
int grid[50][50];

void dfs(int i, int j, int h, int w){
    for (int k = 0; k < 8; k++) {
        int ii = i + offset[k][0], jj = j + offset[k][1];
        if (ii < 0 || ii >= h || jj < 0 || jj >= w) {
            continue;
        }
        if (!visited[ii][jj] && grid[ii][jj]) {
            visited[ii][jj] = 1;
            dfs(ii, jj, h, w);
        }
    }
}


int main(int argc, char *argv[])
{
    
    cin.tie(0);
    ios::sync_with_stdio(false);

    int w, h;

    
    while (cin >> w >> h, w != 0 && h != 0) {
        memset(visited, 0, 50*50*sizeof(int));
        memset(grid, -1, 50*50*sizeof(int));
        
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                cin >> grid[i][j];
            }
        }
        int cnt = 0;
        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {
                if (visited[i][j] || !grid[i][j]) {
                    continue;
                }
                dfs(i, j, h, w);
                cnt++;
            }
        }
        cout << cnt << endl;
    }
    
    return 0;
}

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

int w,h;
int c[50][50];
vector<vector<int> > visited;
int dx[]={1,1,0,-1,-1,-1,0,1};
int dy[]={0,-1,-1,-1,0,1,1,1};

bool dfs(int x,int y){
    if(visited[x][y]) return false;
    visited[x][y]=1;

    for(int d=0;d<8;d++){
        int i=x+dx[d];
        int j=y+dy[d];
        if(0<=i&&i<h&&0<=j&&j<w){
            if(c[i][j]){
                dfs(i,j);
            }  
        }
    }
    return true;
}

int main(){
    visited.assign(50,vector<int>(50,0));
    cin>>w>>h;
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            cin>>c[i][j];
        }
    }
    int cnt=0;
    for(int i=0;i<h;i++){
        for(int j=0;j<w;j++){
            if(c[i][j]){
                cnt+=dfs(i,j);
            }
        }
    }

    cout<<cnt<<endl;
    return 0;
}

C++: #include <cstdio>
#include <algorithm>
#include <iostream>
#include <vector>

using namespace std;
int dx[8]={1,1,1 ,0, 0,-1,-1,-1};
int dy[8]={0,1,-1,1,-1, 1, 0,-1};
int c[55][55];
int w,h;
int res;
void paint(int i,int j,int k){
  if(i<0||j<0)return;
  else if(i>=h||j>=w) return;
  else if(c[i][j]!=1) return;
  c[i][j]=k;
  for(int l=0;l<8;l++) paint(i+dx[l],j+dy[l],k);
  return;
}
void count(int i,int j){
  res++;
  paint(i,j,res);
  return;
}
int main(void){
  int i,j;
  while(scanf("%d %d",&w,&h),w|h){
    res=1;
    for(i=0;i<h;i++){
      for(j=0;j<w;j++){
        scanf("%d",&c[i][j]);
      }
    }
    for(i=0;i<h;i++){
      for(j=0;j<w;j++){
        if(c[i][j]==1){
          count(i,j);
        }
      }
    }
    printf("---\n");
    for(i=0;i<h;i++){
      for(j=0;j<w;j++){
        printf("%d",c[i][j]);
      }
      printf("\n");
    }
    printf(":%d\n",res-1);
  }
  return 0;
}

C++: // http://judge.u-aizu.ac.jp/onlinejudge/description.jsp?id=1160

#include <iostream>
#include <algorithm>
#include <stack>
using namespace std;

int w, h;
bool F[60][60];

struct point {
  int x, y;
};

void init() {
  fill(&F[0][0], &F[0][0]+60*60, 0);
  for (int i=1; i<=h; i++) {
    for (int j=1; j<=w; j++) {
      int temp;
      scanf("%d", &temp);
      F[i][j] = (bool) temp;
    }
  }
}

int solve() {
  int ans = 0;
  for (int i=1; i<=h; i++) {
    for (int j=1; j<=w; j++) {
      if (F[i][j]) {
	stack<point> S;
	point p = { i, j };
	S.push(p);
	while (! S.empty()) {
	  p = S.top();
	  S.pop();
	  F[p.x][p.y] = false;
	  for (int i=-1; i<=1; i++) {
	    for (int j=-1; j<=1; j++) {
	      point q = { p.x + i , p.y + j };
	      if (F[q.x][q.y]) {
		S.push(q);
	      }
	    }
	  }
	}
	ans++;
      }
    }
  }
  return ans;
}

int main() {
  while(scanf("%d%d", &w, &h) != EOF && w && h) {
    init();
    printf("%d\n", solve());
  }
}