#include <fstream>

using namespace std;

int cmmdc(int a, int b) {
	while (a!=b) 
		if (a>b) a=a-b;
		else b=b-a;
	return a;
}

void fractii() {
	ifstream f("fractii.in");
	ofstream g("fractii.out");
	int n, nr;
	f>>n;
	f.close();
	nr=1;
	for (int i=1 ; i<=n ; i++)
		for (int j=1 ; j<i ; j++)
			if (cmmdc(i,j)==1) //{
					nr++;
					//g<<i<<"/"<<j<<" ";
				//}
	g<<nr*2-1<<endl;
	g.close();
}

int main() {
	fractii();
	return 0;
}