#include <iostream>
#include <fstream>
#include <math.h>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int n,i,j,ok,nr,k;
int main()
{f>>n;nr=2*n-1;
  for (i=2;i<=n-1;i++)
   for (j=i+1;j<=n;j++)
   {ok=1;if (j%i!=0)
       for (k=2;k<=sqrt(j);k++ && ok==1){if (i%k==0 && j%k==0)ok=0;}
       else ok=0;
   if (ok==1)nr+=2;
   }
   g<<nr;
   f.close();
   g.close();
    return 0;  f>>n;nr=2*n-1;
  for (i=2;i<=n-1;i++)
   for (j=i+1;j<=n;j++)
   {ok=1;if (j%i!=0)
       for (k=2;k<=sqrt(j);k++ && ok==1){if (i%k==0 && j%k==0)ok=0;}
       else ok=0;
   if (ok==1)nr+=2;
   }
   g<<nr;
   f.close();
   g.close();
    return 0;
}