Instructions: In this task you will be given a passage and a yes/no question based on the passage. You should answer the question using the information from the passage.
Input: passage: A signature page has a line for the signature of a passport holder. A passport is not valid until it is signed by the passport holder. If a holder is unable to sign his passport, it is to be signed by a person who has legal authority to sign on the holder's behalf.
question: is a us passport valid if not signed?
Output:
No