#include <iostream>
#include <fstream>

int cmmdc(int a, int b)
{
    if(!b)
        return a;
    else
        return cmmdc(b, a%b);
}

using namespace std;

main()
{
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    int N, P, Q,contor;
    contor = 0;
    f >> N;
    for(P = 1;P <= N;P++)
        for(Q=P;Q<N;Q++)
            if(cmmdc(P,Q) == 1)
                contor++;
    g << contor * 2;
    return 0;
}