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.

Example input: 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-Lô 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 (1894–1973) 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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Example output: 1
Example explanation: The question refers to the 704th unit and task about war which is decribed by Passage 1.
Q: Question: How long had Britain had control of Hong Kong before returning it to China? Passage 1:The main road going through Wanstead is the A12 and was the site of a Roman villa, whilst Wanstead Manor was a Saxon and Norman manor. It formed part of the Municipal Borough of Wanstead and Woodford in Essex from 1937 until 1965, when Greater London was created. The area has a largely suburban feel, containing open grasslands such as Wanstead Flats, and the woodland of Wanstead Park, part of Epping Forest. The park, with artificial lakes, was formerly part of the estate of a large stately home Wanstead House, built by Richard Child, 1st Earl Tylney, one of the finest Palladian mansions in Britain and the architectural inspiration for Mansion House, London. It was subsequently demolished to pay the gambling debts of a relation of the Duke of Wellington.
 Passage 2:As a result of negotiations and the 1984 agreement between China and Britain, Hong Kong was returned to China and became its first Special Administrative Region on 1 July 1997, under the principle of "one country, two systems". Hong Kong has a different political system from mainland China. Hong Kong's independent judiciary functions under the common law framework. The Hong Kong Basic Law, the constitutional document drafted by the Chinese side before the handover based on the terms enshrined in the Joint Declaration, governs its political system, and stipulates that Hong Kong shall have a high degree of autonomy in all matters except foreign relations and military defence. The declaration stipulates that the region maintain its capitalist economic system and guarantees the rights and freedoms of its people for at least 50 years after the 1997 handover. The guarantees over the territory's autonomy and the individual rights and freedoms are enshrined in the Hong Kong Basic Law, which outlines the system of governance of the Hong Kong Special Administrative Region, but which is subject to the interpretation of the Standing Committee of the National People's Congress (NPCSC).
 Passage 3:He was born to Sir Christopher Ingold and Dr. Hilda Usherwood, and studied for a BSc in Chemistry at the University of London, completing his degree in 1949. He continued his higher education with a PhD in chemistry at Oxford University, which he completed in 1951. Soon after graduation he moved to Canada to begin work with the National Research Council, followed by two years of post-doctoral research at the University of British Columbia. He returned to work for the NRC in 1955 as a research officer, followed by a promotion to head of the Free Radical Chemistry Section. He was awarded the 1968 Petroleum Chemistry Award, the 1988 Linus Pauling Award, and both the Davy Medal and Royal Medal of the Royal Society, the latter for "elucidating the mechanism of reactions involving free radicals". In 1995 he was made an officer of the Order of Canada. He has received honorary degrees from the universities of Guelph, Mount Allison, St Andrews, Carleton, McMaster and Dalhousie.

A:
2