In this task, you're given a question, along with three passages, 1, 2, and 3. Your job is to determine which passage can be used to answer the question by searching for further information using terms from the passage. Indicate your choice as 1, 2, or 3.

Let me give you an example: Question: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin? Passage 1: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Lo during July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
. Passage 2: John Ford (18941973) was an American film director whose career spanned from 1913 to 1971. During this time he directed more than 140 films. Born in Maine, Ford entered the filmmaking industry shortly after graduating from high school with the help of his older brother, Francis Ford, who had established himself as a leading man and director for Universal Studios. After working as an actor, assistant director, stuntman, and prop man often for his brother Universal gave Ford the opportunity to direct in 1917. Initially working in short films, he quickly moved into features, largely with Harry Carey as his star. In 1920 Ford left Universal and began working for the Fox Film Corporation. During the next ten years he directed more than 30 films, including the westerns The Iron Horse (1924) and 3 Bad Men (1926), both starring George O'Brien, the war drama Four Sons and the Irish romantic drama Hangman's House (both 1928 and both starring Victor McLaglen). In the same year of these last two films, Ford directed his first all-talking film, the short Napoleon's Barber. The following year he directed his first all-talking feature, The Black Watch.
. Passage 3: Since the late 1970s, the central part of NYU is its Washington Square campus in the heart of Greenwich Village. Despite being public property, and expanding the Fifth Avenue axis into Washington Square Park, the Washington Square Arch is the unofficial symbol of NYU. Until 2008, NYU's commencement ceremony was held in Washington Square Park. However, due to space constraints, ceremonies are now held at the Yankee Stadium. Important facilities at Washington Square are the Elmer Holmes Bobst Library, designed by Philip Johnson and Richard Foster, who also designed several other structures, such as Tisch Hall, Meyer Hall, and the Hagop Kevorkian Center. When designing these buildings Johnson and Foster also set up a master plan for a complete redesign of the NYU Washington Square campus. However, it was never implemented. Other historic buildings include the Silver Center (formerly known as "Main building"); the Brown Building of Science; Judson Hall, which houses the King Juan Carlos I of Spain Center; Vanderbilt Hall, the historic townhouse row on Washington Square North; The Grey Art Gallery at 100 Washington Square East, housing the New York University art collection and featuring museum quality exhibitions; the Kaufman Management Center; and the Torch Club the NYU dining and club facility for alumni, faculty, and administrators. Just a block south of Washington Square is NYU's Washington Square Village, housing graduate students and junior and senior faculty residences in the Silver Towers, designed by I. M. Pei, where an enlargement of Picasso's sculpture Bust of Sylvette (1934) is displayed.
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The answer to this example can be: 1
Here is why: The question refers to the 704th unit and task about war which is decribed by Passage 1.

OK. solve this:
Question: How many people live in the city where Kirdorf was born? Passage 1:The First Indochina War had raged, as guerrilla warfare, since 19 December 1946. From 1949, it evolved into conventional warfare, due largely to aid from the communists of the People's Republic of China ("PRC") to the north. Subsequently, the French strategy of occupying small, poorly defended outposts throughout Indochina, particularly along the Vietnamese-Chinese border, started failing. Thanks to the terrain, popular support for August Revolution and support for decolonization from bordering China and the U.S.S.R., the Viet Minh had succeeded in turning a "clandestine guerrilla movement into a powerful conventional army", following asymmetric warfare theory laid by Mao Tse Tung, something which previously had never been encountered by the western colonial powers. In October 1952, fighting around the Red River Delta spread into the Thai Highlands, resulting in the Battle of Na San, at which the Viet Minh were defeated. The French used the lessons learned at Na San strong ground bases, versatile air support, and a model based on the British Burma Campaign as the basis for their new strategy. The Viet Minh, however, remained unbeatable in the highland regions of Vietnam, and the French "could not offset the fundamental disadvantages of a roadbound army facing a hill and forest army in a country which had few roads but a great many hills and forests".
Passage 2:On 29 April 1992, a group of Junior soldiers in the Sierra Leone Army led by a 25 year old Captain Valentine Strasser overthrew President Momoh, and Sierra Leone was under Military rule from 1992 to 1996 during the civil war. Sierra Leone returned to a democratically elected government when the military Junta under Brigadier General Julius Maada Bio who had ousted Strasser in a coup in 1996, handed the presidency to Ahmad Tejan Kabbah of the SLPP after his victory in the 1996 Sierra Leone presidential election. However, on 25 May 1997, the Sierra Leone military overthrew President Kabbah in a coup and Major General Johnny Paul Koroma became the country's Head of State. However, in February 1998, a coalition of West African Ecowas armed forces led by Nigeria reinstated President Kabbah by military force, and the leaders of the coup were executed after they were sentenced to death by a Sierra Leone military court. In January 2002, President Kabbah announced the ending of the civil war with the help and support of Ecowas, the British government, the African Union, and the United Nations. Sierra Leone has had an uninterrupted democratic government from 1998 to present.
Passage 3:Emil Kirdorf was born at Mettmann, Rhine Province. His father was a wealthy owner of a weaving mill. He had a brother named Adolf who would be his business partner during his adult life. Kirdorf volunteered a year in 1864 in Hamburg to work in an export enterprise. A year later, he worked in a textile company in Krefeld. The family's mill went bankrupt, mainly because of the management's refusal to introduce mechanical looms. Kirdorf therefore changed to mining industry in which he worked as an accountant. Following the Franco-Prussian War, he became director of Zeche Holland in 1871. Two years later, the entrepreneur Friedrich Grillo offered him the position of commercial director in the Gelsenkirchener Bergwerks-AG (GBAG) company. He became general manager of GBAG in 1893. He steered the company through the Long Depression of the 1870s, and held this position until 1926.

Answer:
3