#include <fstream>
std::ifstream in("fractii.in");
std::ofstream out("fractii.out");
int cmmdc( int a,int b)
{
	while(a!=b)
		if(a>b)
			a=a-b;
		else
			b=b-a;
		return a;
}
int main ()
{
	int n,i,j,k=0;
	in>>n;
	k=n;
	k=k+n/2+1;
	for(i=2;i<=n;i++)
	{
		if(i%2==0)
		for(j=1;j<=n;j=j+2)
			if(cmmdc(i,j)==1)
				k++;
		else
		for(j=2;j<=n;j=j+2)
			if(cmmdc(i,j)==1)
				k++;
	}
	out<<k;
	in.close ();
	out.close ();
return 0;
}