def three_digit(number):
    """ Add 0s to inputs that their length is less than 3.
    :param number:
        The number to convert
    :type number:
        int
    :returns:
        String
    """
    number = str(number)
    if len(number) == 1:
        return u'00%s' % number
    elif len(number) == 2:
        return u'0%s' % number
    else:
        return number