#include<fstream>

using namespace std;

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

long N,Q,nr=0;

int valid(long p,long q)
{
  long a,b;
  int r;
  a=p;
  b=q;
  r=a%b;
  while(r)
  {
    a=b;
    b=r;
    r=a%b;
  }
   if(b==1)
    return 1;
   else
    return 0;
}

void bktr(long P)
{
  long pval;
  if(P<=N){
  for(pval=1;pval<=N;pval++)
  {
    Q=pval;
    if(valid(P,Q))
       ++nr;
  }
  bktr(P+1);

}}
int main()
{
  f>>N;
  bktr(1);
  g<<nr;
  f.close();
  g.close();
  return 0;
}