#!/usr/bin/env python3

from Cryptotools.Utils.utils import gcd


# https://oeis.org/A000010
def phi(n):
    """
        This function count all phi(n)

        Args:
            n (integer): it's the phi(n) value

        Returns:
            Return the phi(n)
    """
    y = 1
    for i in range(2, n):
        if gcd(n, i) == 1:
            y += 1
    return y