#include<fstream>
using namespace std;

int v[1000001];

int main ()
{
    ifstream f("fractii.in");
    ofstream g("fractii.out");

    int i, n, r, c = 0, a, j, b;

    f >> n;

    for(i = 1 ; i <= n/2; ++i)
        {
            a = i;
            for(j = 1 ; j <= n; ++j)
                {
                    b = j;
                    while(r = a % b)
                        {
                            a = b;
                            b = r;
                        }
                    if(b == 1) ++c;
                }
        }
    g <<1 + 2 * c;
}