#include <fstream>
#include <iostream>
using namespace std;

int N, Rez = 0;

void citire()
{
    fstream f;
    f.open("fractii.in");
    f>>N;
}

void scriere()
{
    ofstream g;
    g.open("fractii.out");
    g<<Rez;
}

int cmmdc(int a, int b)
{
    while (a != b)
    {
        if (a < b) b = b - a;
        else a = a - b;
    }

    return a;

}

void rezolvare()
{
    int sum;
    sum = N;
    if (N % 2 == 1) sum += (N/2)*(N/2 + 1);
    else sum += (N/2) * (N/2);
    int i = 3;
    do {

        for (int j = 1; j <= N; j++)
            if (cmmdc(i,j) == 1) sum++;
        i+=2;
    } while (i <= N);
    Rez = sum;
}

int main()
{
    citire();
    rezolvare();
    scriere();
    return 0;
}