#include <iostream>
using namespace std;


int main()
{
    freopen("fractii.in", "r", stdin);
    freopen("fractii.out", "w", stdout);
    long n;
    cin >> n;
    int i, k, b=n;
    for(i=2; i<=n; i++)
    {
          for(k=1; k<=n; k++)
             if(k==1) b++;
             else
                if(k % i!=0 && i % k!=0) b++;
    }
    cout << b;
    return 0;
}