#include<cstdio>

const int NMAX = 1<<17 ;

int vect [ NMAX ] ;

void ciur ( ) 
{
	int i , j ;
	for ( i = 1 ; i <= NMAX ; i ++ )
		vect[i] = i ;
	for ( i = 2 ; i <= NMAX ; i ++ )
		if ( vect[i]==i )
			for ( j = i ; j <= NMAX ; j += i )
				vect[j] = (vect[j] / i ) * (i-1) ;
}

int main ( )
{
	freopen ( "sum.in" , "r" , stdin ) ;
	freopen ( "sum.out" , "w" , stdout ) ;
	int n , i , x ;
	scanf ( "%d" , & n ) ;
	ciur ( ) ;
	return 0;
	for ( i = 1 ; i <= n ; i ++ )
	{
		scanf ( "%d" , & x ) ;
		printf ( "%lld\n" , (long long)2*x*vect [ x ] ) ;
	}
	
	return 0 ;
}