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.

Ex Input:
Question: How long did the battle where George was appointed colonel for last? Passage:Randall enlisted as a private in the 4th Pennsylvania Volunteer Infantry in the April 1861. He then accepted appointment to the 4th U.S. Infantry as second lieutenant in October. He served in New York and Washington, D.C., and in the field with the Army of the Potomac. He was a second lieutenant at the Siege of Yorktown, Battle of Gaines' Mill, Battle of Malvern Hill, Second Bull Run (where he commanded Company C), and Fredericksburg; and a first lieutenant at the Battle of the Wilderness. He was appointed a brevet captain for gallant service in the Battle of Antietam. He served as a major in the 14th New York Heavy Artillery Regiment, part of Major General Ambrose Burnside's IX Corps on the Richmond-Petersburg Front in 1864, and was commander of the regiment at the Battle of the Crater. The Dansville Advertiser reported on 7 September that he assumed command of the regiment on 18 August. This article also reports that he was wounded in the battle on 19 August. He was appointed a brevet lieutenant colonel, and then colonel for gallantry in the Battle of Fort Stedman. He mustered out of the Volunteer service on 26 August, and was appointed captain in the 4th US Infantry on 23 September 1865. Subsequently, he served at Davids' Island Military Reservation, New York Harbor, where he was in December 1867.


Ex Output:
b


Ex Input:
Question: Which US Air Force plane that was shot down in Yugoslavia is the fastest? Passage:An important portion of the 1999 war between Yugoslavia and the NATO coalition involved combat between the Yugoslav Air Force, which was the predecessor of today's Serbian Air Force, and the opposing air forces of NATO. United States Air Force F-15s and F-16s flying mainly from Italian air force bases attacked the defending Yugoslav fighters—usually MiG-29s, which were in bad shape, due to lack of spare parts and maintenance. A total of six Yugoslav MiG-29s were shot down in 1999, of which three were shot down by USAF F-15s, one by a USAF F-16, and one by a RNAF F-16. One aircraft, according to a Serbian documentary, was hit by friendly fire from the ground. Another four were destroyed on the ground. During the course of the air war, Yugoslav anti-aircraft defenses downed a USAF F-16C and an F-117 Nighthawk, the first stealth aircraft to ever be shot down in combat.


Ex Output:
b


Ex Input:
Question: Who was the ruler of South African mandate when it took over the South West Africa German colony? Passage:German Namibians () are a community of people descended from ethnic German colonists who settled in present-day Namibia. In 1883, the German trader Adolf Lüderitz bought what would become the southern coast of Namibia from Josef Frederiks II, a chief of the local Oorlam people, and founded the city of Lüderitz. The German government, eager to gain overseas possessions, annexed the territory soon after, proclaiming it German South West Africa (). Small numbers of Germans subsequently immigrated there, many coming as soldiers (), traders, diamond miners, or colonial officials. In 1915, during the course of World War I, Germany lost its colonial possessions, including South West Africa (see History of Namibia); after the war, the former German colony was administered as a South African mandate. The German settlers were allowed to remain and, until independence in 1990, German remained an official language of the territory alongside Afrikaans and English.


Ex Output:

a