#include<iostream>
#include<fstream>
using namespace std;

ifstream f("fractii.in");
ofstream g("fractii.out");

inline int cmmdc (int a,int b)
{
 while (a!=b)
  if (a>b)
   a=a-b;
  else
   b=b-a;
 return a;
}

void fractii ()
{
    int n, q=1, p=1, k=0, pp, qq;
    f>>n;
    pp=1;
    qq=1;

    while(p<=n && q<=n)
    {
        if(cmmdc (pp,qq)==1)
        {
            if(q!=n)
            {
                ++q;
                ++k;
                qq=q;
            }
            else if(q==n)
            {
                ++p;
                q=1;
                pp=p; qq=1;
                ++k;
            }
        }
        else if(cmmdc(pp,qq)!=1)
        {

            if(q!=n)
            {
                ++q;
                qq=q;
            }
            else if(q==n)
            {
                ++p;
                pp=p;
                q=1;
                qq=q;
            }
        }
    }
    g<<k;
}

int main ()
{
    fractii ();
}