C++ :

#include<cstdio>
#include<cstring>
#include<cmath>
#include<algorithm>
#include<cstdlib>
#include<iostream>
using namespace std;
main ()
{   bool a[100000];
     int j,n;
	//memset(a,0,sizeof(a))；
	 memset(a,0,sizeof(a)); 
	 scanf("%d",&n);
	  for (int i=1;i<=n;i++)
	  {  j=1;
	    while (i*j<=n)  
	    {
	        if (a[i*j]) {a[i*j]=false;} else {a[i*j]=true
	        ;};
	        j++;
	    }
      }
    for (int i=1;i<=n ;i++)
    {
     if (a[i])
      //printf("%d",i);
      printf("%d ",i);
    }
      return 0;
}