class InvalidNumberError(Exception):
    """
    Raised when an invalid number (in the range 32776..65535 inclusive)
    is encountered.
    """
    pass


class EmptyStackError(Exception):
    """Raised when attempting to pop an element from an empty stack."""
    pass

class InvalidNumberError(Exception):
    """
    Raised when an invalid number (in the range 32776..65535 inclusive)
    is encountered.
    """
    pass


class EmptyStackError(Exception):
    """Raised when attempting to pop an element from an empty stack."""
    pass

Raised when an invalid number (in the range 32776..65535 inclusive)     is encountered. Raised when attempting to pop an element from an empty stack.