#include <iostream>
#include <fstream>

using namespace std;
ifstream fin("fractii.in");
ofstream fout("fractii.out");

int prime(int b, int a)
{
    int aux;
    while(b != 0)
    {
        aux = b;
        b = a%b;
        a = aux;
    }

    if(a == 1)
        return 1;
    return 0;
}


int main()
{
    int n;
    int cnt = 0;
    fin >> n;
    for(int i = 1; i < n; i++)
        for (int j = i+1; j<= n; j++)
            if (prime(i, j)) cnt++;
    fout<<2 * cnt + 1;
    return 0;
}