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

int k,n;
int reducibilis(int,int);
void szamol(int l)
{
    int i,j;
    for(i=2;i<=n;i++){
        for(j=i+1;j<=n;j++){
            if(reducibilis(i,j)==1){
                k=k+2;
            }
        }
    }
}

int reducibilis(int a,int b)
{
    int q;
    if(a<b){q=a;a=b;b=q;}
    while(a%b!=0){
        q=a;
        a=b;
        b=q%b;
    }
    return b;
}

int main()
{
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    f>>n;
    k=2*n-1;
    szamol(2);
    g<<k;
}