#include <fstream>
using namespace std;

ifstream input("fractii.in");
ofstream output("fractii.out");
int cmmdc(int a, int b)
{
	int c;
	while(c=a%b)
	{ a=b; b=c; }
	return b;
}
int main(void)
{
	int N,P,Q,T;
	input >> N;
	T=N*2-1;
	for(P=2; P<=N; P++)
		for(Q=2; Q<=N; Q++)
			if(cmmdc(P,Q) == 1)
				++ T;
	output << T;		
	input.close();
	output.close();
	return 0;
}