#include<fstream>
using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");
int main()
{int n,i,j,h,nr,s;
fin>>n;s=n;
for(i=2;i<=n;i++){nr=n;
    for(j=2;j<=i;j++)
        if(i%j==0)
    for(h=1;h<=i/j;h++)
    nr--;
    s+=nr;}fout<<s;
}