#include<fstream>
using namespace std;
int n,m;
ifstream f("fractii.in");
ofstream g("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()
{f>>n;
if(n>1){for(int i=2;i<=n;i++)for(int j=1;j<i;j++)if(cmmdc(i,j)==1)m++;
g<<m*2+1;}
else g<<'1';
return 0;}