#include<fstream.h>
int main()
{
	ifstream fin("fractii.in");
	ofstream fout("fractii.out");
	int n,i,j,s;
	fin>>n;
	s=4*n-5;
	for(i=2;i<=n-2;i+=2)
		for(j=i+3;j<=n;j+=2)
			s+=2;
	for(i=3;i<=n-2;i+=2)
		for(j=i+2;j<=n;j++)
			if(j%i!=0)
				s+=2;
	fout<<s;
	return 0;
}