def dechaffify(chaffy_val, chaff_val = 98127634):
    """ Dechaffs the given chaffed value. 
    chaff_val must be the same as given to chaffify(). 
    If the value does not seem to be correctly chaffed, raises a ValueError. """
    val, chaff = divmod(chaffy_val, chaff_val)
    if chaff != 0:
        raise ValueError("Invalid chaff in value")
    return val