#include <fstream>


using namespace std;

ifstream fin("fractii.in");
ofstream gout("fractii.out");

bool prime(int i, int j)
{
    int minimul = i > j ? i : j;
    for (int d=2;d<=minimul/2;d++)
        if (i%d == 0 && j%d == 0)
            return false;
    return true;
}

int main()
{
    int n, i, j, cnt;
    fin >> n;
    cnt = 2*n - 1;
    for (i=2;i<=n;i++)
        for (j=i+1;j<=n;j++)
            if (prime(i,j))
                cnt+=2;
    gout << cnt;
}