Classify the input text into either disfluent questions or proper questions. A disfluent question is a question that has some interruptions in it while framing. A proper question is the correct form of the question without any disfluency.
--------
Question: Why are coastal species tough?

Answer: proper


Question: What vitamin excuse me What gene is expressed by the B-cell?

Answer: disfluent


Question: What did the NIF try to divide I mean unify Islamist opposition against?

Answer:
disfluent