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;

struct Graph{
	vector<vector<int>> fld;
	
	Graph(int h,int w) : fld( h,vector<int>(w) ){}
	
	void dfs(int x, int y){
		
		fld.at(x).at(y) = 2;
		for(int i=-1; i<=1; i++){
			for(int j=-1; j<=1; j++){
				int h = fld.size();
				int w = fld.at(0).size();
				if(x+i<0||h-1<x+i||y+j<0||w-1<y+j) continue;
				if(fld.at(x+i).at(y+j)!=1) continue;
				dfs(x+i,y+j);
			}
		}
		return;
	}
	
};

int main() {
	while(1){
		int w,h;
		cin >> w >> h;
		if(w==0&&h==0) break;
		
		Graph graph(h,w);
		for(int i=0; i<h; i++){
			for(int j=0; j<w; j++){
				int s;
				cin >> s;
				graph.fld.at(i).at(j) =  s;
			}
		}
		
		int cnt{};
		for(int i=0; i<h; i++){
			for(int j=0; j<w; j++){
				if(graph.fld.at(i).at(j)==1) {
					graph.dfs(i,j);
					cnt++;
				}
				
			}
			
		}
		cout << cnt << endl;
	}
	
}

C++: /*
AizuOnline A1160
How many islands
13/03/13 RUNTIME Error
*/
#include <stdio.h>
#include <stdlib.h>

int width = 10;
int height = 10;

char kajuen[100][101];

char search_next(int * x,int * y)
{
  int i,j;
/* printf("SEARCH =%d %d\n",*x,*y); */
  i = *x;j = *y;
  goto START;
  for(i=0;i<height;i++)
    for(j=0;j<width;j++)
      {
      START:
	//	printf("SEARCH =%d %d:",i,j);
	if(kajuen[i][j]=='1')
	  { *x=i;*y=j;
	    return(kajuen[i][j]);
	  }
      }
  return(0);
}

void paint(int p,char f,int x,int y)
{
  int i,j;

#ifdef DEBUG2
  printf("P=%d %d %c %c",x,y,p,f);
  printf("F=%c N=%c %c %c\n",kajuen[x+1][y],kajuen[x][y+1],owner[x+1][y],owner[x][y+1]);
#endif
  //owner[x][y]=p+'A';
  kajuen[x][y]='0';
  for(i=x-1;i<=x+1;i++)
    for(j=y-1;j<=y+1;j++)
      if((i >=0) && (i <height) && (j >= 0) && (j <width) && !(x==i&&y==j))
	{
	  //printf("p:%d %d %d %d",x,y,i,j);
	if(kajuen[i][j] == f)
	  paint(p,f,i,j);
	}
}

int devide_kajuen()
{
  int x,y;
  char person;
  char f;

  
  x=0;y=0;
  person = 0;
  while(f=search_next(&x,&y) != 0)
    {   
      f = kajuen[x][y];
      paint(person,f,x,y);
      person ++;

    }
  return(person);
}
void clear_table()
{
  int i,j;
  for(i=0;i<100;i++)
      for(j=0;j<101;j++)
      {
        kajuen[i][j]='\0';
      }   
}
main()
{
  int n;
  int i,j;


  while(EOF != scanf("%d %d",&width,&height) && (width || height))
    {
      clear_table();
      for(i=0;i<height;i++)
	for(j=0;j<width;j++)
	  {  scanf(" %c",&(kajuen[i][j])); 
	  }      

      n = devide_kajuen();
      printf("%d\n",n);      
    }

  return(0);
}