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-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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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 features did Brecht and Dudow work on together? Passage 1:Boulding maintained his links with football and trained with Doncaster Rovers, and in 1998 he joined non-league Hallam near his home in Sheffield. His form at Hallam attracted the interest of a number of league clubs, and Boulding was offered a trial by Mansfield Town. He was given a contract by the Division Three side and turned professional in 1999, which brought an end to his tennis career. He made his debut with Mansfield in a League Cup game against Nottingham Forest on 11 August 1999 as a late substitute for Gary Tallon, before his first league game came three days later against Cheltenham Town. He had to wait until his 12th game as a professional to register his first goal when he scored in a 2–1 victory over Shrewsbury Town on 23 October. He eventually finished his first season with six goals with Mansfield coming 17th but 17 points above Carlisle United, the only side to be relegated out of The Football League.
 Passage 2:Jones was selected by the Dallas Cowboys in the first round (24th overall) of the 1992 NFL Draft, becoming the first player from East Carolina University to be drafted that high. The team moved Ken Norton Jr. to outside linebacker, allowing him to become the second rookie (Eugene Lockhart) in Cowboys history to start at middle linebacker, and the second rookie (Lee Roy Jordan) linebacker in franchise history to start in a season-opener. He helped the Cowboys establish the top defense in the league in 1992, was named NFC rookie of the year and was selected to the NFL All-rookie team. He started 13 out of 15 games, posting 108 tackles (second on the team), one sack, 2 tackles for loss, 4 quarterback pressures, one pass defensed and one fumble recovery. He had 16 tackles against both the Philadelphia Eagles and Kansas City Chiefs.
 Passage 3:Dudow was born in Zaribrod, Bulgaria (today Dimitrovgrad, Serbia). In 1922, he emigrated to Berlin with the intention of becoming an architect. He gave up this plan and began studying theatre in 1923, first under Emmanuel Reicher, and then, from 1925 to 1926, as a theatre studies student under Max Herrmann at the university. He worked with Leopold Jessner and Jürgen Fehling, served as a chorus member under Erwin Piscator, and was a director's assistant to Fritz Lang on the production of Metropolis. During this time, Dudow also ran a bookstore with his wife and worked as a foreign correspondent for a Bulgarian newspaper. In 1929, he visited the Soviet Union, where he met Vladimir Mayakovsky and Sergei Eisenstein in Moscow and eventually, Bertolt Brecht. After his return from the USSR, Dudow directed Brecht's theatrical piece, The Decision (Die Massnahme), and began his film directing career. He was commissioned by the left-wing, Soviet-German production company Prometheus-Film to direct a short film, Wie der Berliner Arbeiter wohnt (1929), as part of the documentary series Wie lebt der Berliner Arbeiter? Dudow's first feature, Kuhle Wampe (To Whom Does the World Belong?, 1932) was a collaboration with Brecht (who provided the script and helped finance the project), Hanns Eisler, and Ernst Ottwalt. It was banned because it was perceived as being politically subversive. 

Answer:
3