#include <fstream>

using namespace std;

ifstream f("fractii.in");
ofstream g("fractii.out");

int cmmdc(int a,int b)
{
    int r;
    while(b!=0)
    {
        r=a%b,a=b,b=r;
    }
    return a;
}

int main()
{
    int N;
    f>>N;
    int nr=2*N-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;
}