#include <fstream.h>
long long cmmdc(long long x,long long y)
{ long long r;
  r=x%y;
  while (r!=0)
	{ x=y;
	  y=r;
	  r=x%y;
	}
  return y;
}
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;
}