#include <fstream.h>
long n,sol,i,j;

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

int main()
{f>>n;
sol=n*2-1;
for (i=2;i<=n;i++)
  for (j=2;j<=n;j++)
    if (i%j==0);
  else
   if (j%i==0);
     else
      sol++;
g<<sol;
return 0;
}