#include <fstream>

using namespace std;
 int cmmdc(unsigned  int p,unsigned int q){while(p!=q){if(p>q) p=p-q; else q=q-p;}return p;}
int main()
{unsigned int p,n,l,q;

ifstream a("fractii.in");
ofstream b("fractii.out");
a>>n;
a.close();
l=2*n-1;

for(p=2;p<=n-1;p++){for(q=p+1;q<=n;q++){if(cmmdc(p,q)==1) l=l+2;}}
b<<l;


b.close();
    return 0;
}