#include <fstream>

using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");

int CMMDC(int a, int b)
{
	while(b != 0)
    {
		int r = a % b;
        a = b;
        b = r;
	}
    return a;
}

int main()
{
	int n, fraction = 1;
	fin >> n;
	for(int i = 1; i <= n; ++i)
		for(int j = i + 1; j <= n; ++j)
			if(CMMDC(i, j) == 1)
				fraction += 2;
	fout << fraction;
	return 0;
}