#include <fstream>
#include<math.h>

using namespace std;

int prime(int nr1,int nr2)
{
  while(nr1!=0)
  {
    int r=nr2%nr1;
    nr2=nr1;
    nr1=r;
  }
  if(nr2!=1) return 0;
  else return 1;
}

int main()
{


  int s,i,j;
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    int n;
    f>>n;
    s=1;
for(i=2;i<=n;i++)
  for(j=1;j<i;j++)
        if(j==1||prime(i,j)) s=s+2;




      g<<s;
      g.close();
      f.close();

    return 0;
}