A question that is free of any grammatical or logcal errors, should be labeled 'yes', otherwise it should be indicated as 'no'. A question is grammatically correct if all its entities i.e. nouns, verbs, adjectives, prepositions, pronouns, adverbs are at appropriate position. A question is logically correct if the semantic makes sense.

Input: Consider Input: Sentence: The NMCC learned about United 93 from the White House. 
Question: Is United 93 still operational?

Output: Yes.


Input: Consider Input: Sentence: In a matter of 48 hours, Alexander II planned to release his plan for the duma to the Russian people. 
Question: What did Alexander II do before releasing his plan?

Output: Yes.


Input: Consider Input: Sentence: He tried to halt the Dayaks' piracy and head-hunting while defending their more ""morally acceptable"" customs. 
Question: How often does he defend their acceptable customs?


Output: Yes.


