#include<fstream.h>

int n, c;

void citire()
{
  ifstream in("fractii.in");
  in>>n;
  in.close();
}

int prim(int a, int b)
{
  int d,c;
  if (a==1 || b==1) return 1;
  if (a%2==0 && b%2==0) return 0;
  if (a>b) c=b;
    else if (a<c) c=a;
	    else return 0;
  for (d=3; d<=c; d+=2)
     if (b%d==0 && a%d==0) return 0;
  return 1;
}


void prelucrare()
{
  int i, j;c=2*n;
  for (i=2; i<=n; i++)
    for (j=i; j<=n; j++)
      if (prim(i,j)==1) c+=2;
}



void afis()
{
  ofstream out("fractii.out");
  out<<c-1;
  out.close();
}

int main()
{
  citire();
  prelucrare();
  afis();
  return 0;
}