#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;
	unsigned int nr_fractii=0;
   ifstream f("fractii.in");
   ofstream f2("fractii.out");
   f>>n;
           for(q=1;q<=n;q++)
           if(q%2==0)
           { 	for(p=1;p<=n; p+=2)
           			if(cmmdc(p,q)==1)
              			nr_fractii++;}
              else
              	{nr_fractii+=q-1;
                for(p=2;p<=n; p++)
           			if(cmmdc(p,q)==1)
              			nr_fractii++;}
           f2<<nr_fractii;
   
   return 0;
}