#include <fstream.h>

int cmmdc(long a, long b)
{  long r;
	while(b)
   {	r=a%b;
      a=b;
      b=r;
   }
   return a;
}

int main()
{	long n, p=1, q=1, nr_fractii=0;
   ifstream f("fractii.in");
   ofstream f2("fractii.out");
   f>>n;
   while(p<=n)
   {
   	if(cmmdc(p,q)==1)
      	nr_fractii++;
      q++;
      if(q>n)
      {	q=1;
      	p++;
      }
   }
   f2<<nr_fractii;
   return 0;
}