You will be given a definition of a task first, then some input of the task.
In this task, you're given a question, along with a context passage. The passage will not have a direct answer to the question, but can include some information and a clue for the answer. Assuming you can only obtain information about one entity in the passage, your job is to determine whether information from the passage can be used to answer the question. Indicate your choice as 'a' for Yes or 'b' for No.

Question: How many aircraft are part of the military branch that Coward was commissioned into in 1937? Passage:Coward was commissioned into the Royal Air Force as an acting pilot officer (on probation) on 28 January 1937. He joined No. 19 Squadron based at RAF Duxford as a pilot flying the Gloster Gauntlet, a single seat biplane. His commission was confirmed and he was regraded as a pilot officer on 16 November 1937. Having shown his artistic skill through caricatures of his comrades, he was tasked with painting the squadron badge on the canvas of the biplanes. However, after weeks of work, the Munich Crisis occurred and the biplanes, and their recently painted badges, were painted over in camouflage. His squadron was the first to be equipped with the Supermarine Spitfire, which entered service on 4 August 1938. He was promoted to flying officer on 16 June 1939.

Output:
a