#include<fstream>
using namespace std;

int cmmdc(int a,int b){
	if(a%b==0)
		return b;
	else
		return cmmdc(b,a%b);
	}

int totient(int n){
	int s=0;
	for(int i=1;i<=n;i++)
		if(cmmdc(i,n)==1)
			s++;
	return s;
	}
		
int main(){
	int n,c=-1,i,j;
	ifstream in("fractii.in");
	in>>n;
	in.close();
	for(i=1;i<=n;i++){
		c+=totient(i);
		}
	ofstream out("fractii.out");
	out<<c*2+1;
	out.close();
	return 0;
	}