#include <iostream>
#include <fstream>
using namespace std;
int cmmdc(int a,int b)
{
    while (a != b)
    if (a>b)
        a = a - b;
    else b = b - a;
    return a;
}
int main()
{
    int n, c = 0,i,j;
    ifstream f("fractii.in");
    ofstream g("fractii.out");
    f >> n;
    for (i = 2; i <= n;i++)
    for (j = 1; j <i; j++)
    if (cmmdc(i, j) == 1)
        c++;
    g << c*2+1;
 
}