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

int cmmdc(int a, int b)
{
    int r;
    r=a%b;
    while(r)
    {
        a=b;
        b=r;
        r=a%b;
    }
    return b;
}

int main ()
{
    ifstream read("fractii.in");
    ofstream write("fractii.out");
    int n;

    read>>n;
    int count = 2*n - 1;
    for(int i=2; i<=n; i++)
    {
        for(int j=i+1; j<=n; j++)
        {
            if(cmmdc(i,j)==1)
            {
                count+=2;
            }
        }
    }
    write<<count;

    return 0;
}