#include <iostream>
#include <fstream>

using namespace std;

ifstream f("fractii.in");
ofstream g("fractii.out");
int p,q,n,nr;

int main()
{
    f>>n;
    nr=n;
    for(p=2;p<=n;++p)
    {
        for(q=1;q<=n;++q)
            if(p<q)
               {if(q%p!=0)
                    nr++;}
            else
                {if(p%q!=0)
                    nr++;}
    }
nr=nr+(n-1);
g<<nr;
f.close();
g.close();
return 0;
}