#include <fstream.h>

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

long n,i,j,total;

void citire()
{f>>n;}

long afla (long k)
{long nr=0;
 for (j=2;j<=n;j++)
  if (j%k!=0 && k%j!=0) nr++;
 return nr;
}

int main()
{citire();
 total=2*n-1;
 for (i=2;i<=n;i++)
  total+=afla(i);
 g<<total;
return 0;
}