#include <iostream>
#include<fstream>



using namespace std;

ifstream f;
ofstream g;

long int k,i,j,n;


long int ired(long int a,long int b)
        {
        if(b==0)return a;
        else ired(b,a%b);
        }


int main()
{
f.open("fractii.in");
g.open("fractii.out");

f>>n;

k=0;
for(i=1;i<=n;i++)
    for(j=i;j<=n;j++)if(ired(i,j)==1)k++;

g<<2*k-1;
g.close();
}