#include <fstream>
using namespace std;
ifstream f1("fractii.in");
ofstream f2("fractii.out");
int cmmdc(int a, int b)
{
    int rest;
    while (b!=0)
    {
        rest=a%b;
        a=b;
        b=rest;
    }
    return a;
}
int main()
{
    int n,i,j;
    long int suma;
    suma=0;
    f1>>n;
    for (i=1; i<=n; i+=1)
        for (j=i+1; j<=n; j+=1)
            if (cmmdc(i,j)==1) suma+=1;
    suma=suma*2+1;
    f2<<suma;
    f1.close();
    f2.close();
    return 0;
}