#include <iostream>
#include <fstream>
using namespace std;
int main()
{
    fstream f1,f2;
    int n,s,i,j,m,t;
    f1.open("fractii.in",ios::in);
    f1>>n;
    f1.close();
    s=0;
    for (i=1;i<=n;i++) {
        for (j=1;j<=n;j++) {
            if (j==1 || i==1) {
                           s++;
                           }
            }
        }
    for (m=2;m<=n;m++) {
        for (t=2;t<=n;t++) {
            if (m%t>0) {
                       s++;
                       }
            }
        }
    f2.open("fractii.out",ios::out);
    f2<<s-1;
    f2.close();
    return 0;
}