#include <fstream.h>
long long cmmdc(int x,int y)
{ while (x!=y)
	if (x>y) x=x-y;
	else y=y-x;
  return x;
}
int main()
{ long long n,i,j,nr;
  ifstream f("fractii.in");
  f>>n;
  f.close();
  nr=0;
  for (i=1;i<n;i++)
	for (j=i+1;j<=n;j++)
		if (cmmdc(i,j)==1) nr=nr+2;
  nr++;
  ofstream g("fractii.out");
  g<<nr;
  g.close();
  return 0;
}