#include <fstream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int pr(int a, int b)
{
	int r=b;
	while(a%b!=0) {r=a%b; a=b; b=r;}
	return r;
}
int main()
{
	int n;
	f>>n;
	int k=2*n-1,i,j;
	for(i=2;i<=n;i++) for(j=i+1;j<=n;j++) if(pr(i,j)==1) k+=2;
	g<<k;
	return 0;
}