#include <fstream>
#include <iostream>
using namespace std;
ifstream f("fractii.in");
ofstream g("fractii.out");
int n;
long long nr;

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

int main()
{
    f>>n;
    nr=2*(n-1)+1;
    for(int i=2;i<n;i++)
        for(int j=i+1;j<=n;j++)
            if(cmmdc(i,j)==1)
                nr+=2;
    g<<nr;
    return 0;
}