#include<iostream>
#include<fstream>
using namespace std;
int cmmdc(int a,int b)
{
    while(a!=b)
    if(a>b) a=a-b;
    else b=b-a;
    return a;
}
int main()
{
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    int i,j,n,nr=0;
    f>>n;
    for(i=2;i<=n-1;i++)
    for(j=i+1;j<=n;j++)
    if(cmmdc(i,j)==1) nr=nr+2;
    g<<nr+2*n-1;
    return 0;
}