Definition: 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.
Input: Question: When did EC Pickering start working at Harvard? Passage 1:Dushanki's father was blinded during World War I and could not provide for the large family. Therefore, after graduating from the 6th grade, Dushanski began working. This early exposure to manual labor pushed him into communism–socialism and, in 1934, he joined the illegal Lithuanian branch of the Komsomol (Communist Union of Youth) and helped distributing underground communist publications. For such communist activities he was arrested in June 1936. First, he was jailed in a juvenile prison; later he was transferred to prisons in Šiauliai and Raseiniai. While in prison, Dushanski joined the Lithuanian Communist Party in 1938. He was released when Soviet Union occupied Lithuania in June 1940 and was given a job as an assistant security officer at the NKVD office in Telšiai. His duties included securing the Soviet Union – Nazi Germany border. He was involved in mass arrests of the "enemies of the people" and the June deportation. Conflicting witnesses testimony implicated Dushanski in the Rainiai massacre, one of the many NKVD prisoner massacres at the beginning of the German invasion of the Soviet Union. According to Dushanski, at the time he was returning from a vacation in Crimea and was attempting to evacuate his family from Šiauliai into Russia. However, the train did not leave the station and his parents and three siblings perished during the Holocaust; only his brother Jacob survived.
 Passage 2:Howard was born to Ossian Gregory Howard, a lawyer, and Lucy Denham Thurber on 11 June 1857. His relatives from his mother's side included the Harvard astronomer E.C. Pickering while other distant relatives included Senator J.M. Howard and President William Howard Taft. Shortly after his birth, the family moved from Rockford, to Ithaca, New York where his father worked with a law firm. Howard attended Ithaca Academy. An interest in insect collecting encouraged by his parents with the gift of The Butterfly Hunters by Mary Treat at the age of 10 followed by more books and at the age of 13, along with another collector friend, recorded the introduction of the European cabbage butterfly (Pieris rapae) in the Catskill region. Along with his friends, he founded the Ithaca Natural History Society to meet and discuss papers and insects. While out collecting one day, he met John Henry Comstock, who invited him to his lab at Cornell University. Howard enrolled in Cornell in September 1873, three years after the death of his father, and following the advice of his mother's friends, went to study civil engineering. Doing poorly in differential calculus made him drop engineering and he began to study other subjects including French, German, and Italian. He then joined Comstock's lab as the first research student and graduated in June 1877 with a thesis on respiration in the larva of Corydalis cornutus. He worked with Burt Green Wilder and Simon Henry Gage and received a masters at Cornell. In the 1880s, he also attended Columbian College (now George Washington University) for medicine, although he didn't complete it. He however received an honorary MD from the same university in 1911 for his contribution to medical entomology. 
 Passage 3:The House of Lancaster was the name of two cadet branches of the royal House of Plantagenet. The first house was created when Henry III of England created the Earldom of Lancasterfrom which the house was namedfor his second son Edmund Crouchback in 1267. Edmund had already been created Earl of Leicester in 1265 and was granted the lands and privileges of Simon de Montfort, 6th Earl of Leicester, after de Montfort's death and attainder at the end of the Second Barons' War. When Edmund's son Thomas, 2nd Earl of Lancaster, inherited his father-in-law's estates and title of Earl of Lincoln he became at a stroke the most powerful nobleman in England, with lands throughout the kingdom and the ability to raise vast private armies to wield power at national and local levels. This brought himand Henry, his younger brotherinto conflict with their cousin Edward II of England, leading to Thomas's execution. Henry inherited Thomas's titles and he and his son, who was also called Henry, gave loyal service to Edward's sonEdward III of England.

Output:
2