#include<fstream>
using namespace std;
unsigned long cmmdc(unsigned long m,unsigned long n){
  if(n%2==0)
    if(m%2==0)
      return 0;

  if(!n) return m;
  else return cmmdc(n,m%n);

}
int main(){
  unsigned long n,i,j,count=0;
  ifstream f("fractii.in");
  f>>n;
  f.close();
  for(i=3;i<=n;i++)
    for(j=i+1;j<=n;j++)
      if(cmmdc(i,j)==1)	count+=2;
  count=count+n+(n/2)+n%2;
  ofstream g("fractii.out");
  g<<count<<'\n';
  g.close();
  return 0;

}