//#include <iostream>
#include <fstream>
using namespace std;

int main()
{
ifstream f("fractii.in");
ofstream g("fractii.out");
int n;
f>>n;
// 2n-1 fractii initiale
int numitor=2,suma=0;

do
{

for(int i=2;i<=n;i++)
{if(numitor>i)
    {if(numitor%i) suma++;}
else if(numitor<i)
    {if(i%numitor) suma++;}
}

numitor++;

}while(numitor<=n);

suma=suma+2*n-1;
g<<suma;

}