You are given a sentence from a conversation between a human and a virtual assistant. Your task is to identify whether the sentence is a question or not. Answer with Yes or No.

Example Input: Ok ,That's great. I need to know its director? who is he?
Example Output: Yes

Example Input: Did they serve liquor and what kind of food do they serve?
Example Output: Yes

Example Input: No. Thank you
Example Output:
No