/* package whatever; // don't place package name! */
 
import java.util.*;
import java.lang.*;
import java.io.*;
 
/* Name of the class has to be "Main" only if the class is public. */
class Ideone
{
	public static void main (String[] args) throws java.lang.Exception
	{
String z="";for(int i=2,s;i<1000;i++)l:{for(s=2;s<i;s++)if(i%s==0)break l;System.out.print(z+i);z=":";}
	}
}