#include<fstream>   
using namespace std;   
const int N=20;
int main()   
{   
    ifstream in("fractii.in");   
    ofstream out("fractii.out");   
    char c[N];
	int n,i,j,x,l,nr=0,q;   
   	in>>n;   
	for (i=1;i<=n;i++)
	{l=1;
	q=i;
	x=2;
	while (x<=q)
	{if (q%x==0)
	{c[l]=x;
	l++;
	while (q%x==0)
	q=q/x;}
	x++;}
	for (j=1;j<=l;j++)
	if (i%c[j]!=0) nr++;}
	out<<nr*2+1;
	in.close();   
	out.close();   
    return 0;   
}