using namespace std;
#include <fstream>

long int euclid(long int a, long int b)
{
        long int c;
        while(b)
        {
                c = a % b;
                a = b;
                b = c;
        }
        return a;
}

int main()
{
        long int n = 0, m = 0, i = 0, j = 0;
        ifstream fin("fractii.in");
        ofstream fout("fractii.out");
        fin >> n;
        for (i = 2; i <= n; i++)
         for (j = i + 1; j <= n; j++)
                if (euclid(i, j) == 1) m++;
        m = m * 2;
        m += n + n - 1;
        fout << m << "\n";
        fin.close();
        fout.close();
        return 0;
}