#include <iostream>
#include <fstream>
#define lim 1000000
using namespace std;

ifstream fin("fractii.in");
ofstream fout("fractii.out");

int n;

bool Ireductibil(int a, int b)
{
    //verificam daca a/b e ireductibil;
    int r=0;
    while(b!=0)
    {
        r=a%b;
        a=b;
        b=r;
    }
    if(a==1)
    return true;
    else return false;
}
int fr=0, V[lim];
void Back(int A)
{ V[A]=1;
   while(V[A]<n+1)
    {
        if(Ireductibil(A,V[A]))
           fr++;

        V[A]=V[A]+1;
    }
  if(A<n)
   Back(A+1);

}

int main()
{
    fin>>n;
    Back(1);
    fout<<fr;
    return 0;
}