(budget, exchanging_value)
:param budget: float - amount of money you own.
    :param exchanging_value: int - amount of your money you want to exchange now.
    :return: float - amount left of your starting currency after exchanging.
def get_change(budget, exchanging_value):
    """

    :param budget: float - amount of money you own.
    :param exchanging_value: int - amount of your money you want to exchange now.
    :return: float - amount left of your starting currency after exchanging.
    """

    pass
def get_change ( budget , exchanging_value ) : pass