#include?
#include?
#include?

using?namespace?std;

bool?ZhiShu?（unsigned?long?n?）?{
	if?（n<2）?{
		return?false?;
	}
	for?（unsigned?long??solo?=?2?;?solo?		if?（n%solo==0）?{
			return?false?;
		}
	}
		return?true?;
		
	
}
unsigned?long?main?（）?{

unsigned?long?ceshi;
cin>>ceshi;
if?（ceshi?	Sleep?（1000）?;
	return?0?;
}
for（unsigned?long?i?=?2?;?i?<=?ceshi?;?i+=2）{
	if（i?		cout<<““;
	}
	els