You will be given a definition of a task first, then some input of the task.
We would like you to assess the QUALITY of each of the following argument (discussing Gay Marriage) and determine if the argument is Valid or Invalid. A valid argument is clearly interpretable and either expresses an argument, or a premise or a conclusion that can be used in an argument for the topic of gay marriage. An invalid argument is a phrase that cannot be interpreted as an argument or not on the topic of gay marriage.

As Stanley Kurtz convincingly argues, however, the slippery slope following gay marriage will lead to polyamory rather than traditional polygamy, because ��_��__��_��__��_��__what gay marriage is to homosexuality, group marriage is to bisexuality:��_��__��_��__
Output:
Valid