Given the task definition, example input & output, solve the new input case.
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: 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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Output: 1
The question refers to the 704th unit and task about war which is decribed by Passage 1.

New input case for you: Question: How long did the time period last in which a huge ice shelf melted between 11,000 and 8,000 BC? Passage 1:It was the 12th New Zealand Grand Prix, doubled as the opening round of the 1965 Tasman Series. The race attracted 19 starters, including several overseas based drivers and teams. A large contingent of cars from Australia competed, including Frank Gardner competing for Alec Mildren Racing. Lex Davison and Leo Geoghegan brought across their own teams, while 1962 Formula One world champion, British racer Graham Hill race a Brabham for David McKay's Scuderia Veloce team. Star attraction though was the appearance of Team Lotus with their lead driver, 1963 World Champion, Jim Clark. Local honour was upheld by Bruce McLaren, who in an early iteration of the later McLaren team brought a pair of factory supported Coopers to race with American racer, the 1961 World Champion Phil Hill as his number two. The race was won by Graham Hill, his first victory in the NZGP. Gardner finished second to be the first 'antipodean' while first New Zealander was domestic series racer Jim Palmer in a career highlight as Brabham racing cars clean swept the podium.
 Passage 2:Iris Chang was the daughter of two university professors, Ying-Ying Chang and Dr. Shau-Jin Chang, who emigrated from Taiwan to the United States. Chang was born in Princeton, New Jersey and raised in Champaign-Urbana, Illinois. Chang grew up hearing stories about the Nanking massacre, from which her maternal grandparents managed to escape. When she tried finding books about the subject in Champaign Public Library, she found there were none. She attended University Laboratory High School of Urbana, Illinois and graduated in 1985. She was initially a computer science major, but would later switch to journalism, earning a bachelor's degree at the University of Illinois at Urbana-Champaign in 1989. During her time in college she also worked as a New York Times stringer from Urbana-Champaign, and wrote six front-page articles over the course of one year. After brief stints at the Associated Press and the Chicago Tribune, she pursued a master's degree in Writing Seminars at Johns Hopkins University. She then embarked on her career as an author and lectured and wrote magazine articles. She married Bretton Lee Douglas, a design engineer for Cisco Systems, whom she had met in college, and had one son, Christopher, who was 2 years old at the time of her suicide. She lived in San Jose, California in the final years of her life.
 Passage 3:The first inhabitants were the Ahrensburg culture (11th to 10th millennia BC), which was a late Upper Paleolithic culture during the Younger Dryas, the last period of cold at the end of the Weichselian glaciation. The culture is named after the village of Ahrensburg, north-east of Hamburg in the German state of Schleswig-Holstein, where wooden arrow shafts and clubs have been excavated. The earliest traces of human occupation in Norway are found along the coast, where the huge ice shelf of the last ice age first melted between 11,000 and 8,000 BC. The oldest finds are stone tools dating from 9,500 to 6,000 BC, discovered in Finnmark (Komsa culture) in the north and Rogaland (Fosna culture) in the south-west. However, theories about two altogether different cultures (the Komsa culture north of the Arctic Circle being one and the Fosna culture from Trøndelag to Oslofjord being the other) were rendered obsolete in the 1970s.

Output:
3