def even_or_odd(number: int) -> str:
    """
    Determine and return whether a number is even or odd.

    Parameters
    ----------
    number : int
        The number to check. May be negative or zero.

    Returns
    -------
    str
        'Even' if the number is even, 'Odd' if the number is odd.

    Examples
    --------
    >>> even_or_odd(4)
    'Even'
    >>> even_or_odd(3)
    'Odd'
    """
    raise NotImplementedError("Replace this line with your code.")