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: What is the population of the city which hosted the socialist congress Lunacharsky attended in 1907? Passage 1:Halleck's plan, finalized in January 1864, called for Banks to take 20,000 troops up from New Orleans to Alexandria, including the 47th Pennsylvania Infantry, the only regiment from the Keystone State to fight in this campaign, on a route up the Bayou Teche (in Louisiana, the term bayou is used to refer to a slow moving river or stream), where they would be met by 15,000 troops sent down from Major General William T. Sherman's forces in Vicksburg, Mississippi, and under the command of Brigadier General A.J. Smith. Smith's forces were available to Banks only until the end of April, when they would be sent back east where they were needed for other Union military actions. Banks would command this combined force of 35,000, which would be supported in its march up the Red River towards Shreveport by Union Navy Rear Admiral David Dixon Porter's fleet of gunboats. At the same time, 7,000 Union troops from the Department of Arkansas under the command of Major General Frederick Steele would be sent south from Arkansas to rendezvous with Banks in his attack on Shreveport, and to serve as the garrison for that city after its capture.
 Passage 2: November 1915, von Brincken married again to the San Francisco socialite Milo Abercrombie (1895-1977). Born in Houston, Texas, Milo was the niece of John W. Abercrombie, U.S. congressman from Alabama and acclaimed by noted portraitist Harrison Fisher as "California's greatest beauty". They had two children, Wilhelm Friedrich (1918-1980) and Maria A. (1917-2010). She divorced von Brincken in 1919 during his imprisonment and legally changed her and their two children's last name back to her maiden name, Abercrombie, so her children would not be "ashamed" of their name. Despite the divorce, von Brincken remained devoted to his former wife and she was able to remarry again, thanks to him. When the Roman Catholic Church forbade Abercrombie's intended marriage to U.S. Navy lieutenant Lyman K. Swenson, due to her divorce, von Brincken came forth and disclosed his earlier marriage to Alice Roedel. As both Roedel and von Brincken were Catholic, that marriage was sanctioned by the Church. Thus, the Church did not recognize von Brincken's later marriage to Abercrombie. Abercrombie and Swenson, who had both refused to marry unless it was sanctioned by the Catholic Church were then free to wed. Abercrombie and Swenson were married on August 11, 1920 by Father John Byrne at St Mary's Cathedral in San Francisco. At the wedding dinner that night, von Brincken's young son with Abercrombie, referred to as "John" and "Buster" in the press, was a "guest of honor" and toasted by his new stepfather and the officers of the submarine H-6 that he commanded, pledging, "the little chap's future to the uniform of blue." Swenson and Abercrombie had two children, Lyman K. Jr. ("Robert") and Cecilia. Abercrombie obtained an interlocutory decree of divorce from Swenson in May 1925, with the final decree a year later. Several months later, in October 1925, the newspapers speculated that Abercrombie would marry another naval officer, Lieutenant Commander Hugo W. Koehler, reputed to be the "wealthiest officer" in the Navy. The third generation of a wealthy St. Louis brewery family, Koehler had been a naval intelligence and U.S. State Department spy in South Russia during the Russian Revolution. Swenson had introduced Milo Abercrombie to Koehler in Honolulu. Koehler was in Panama with his ship, USS West Virginia (BB-48) when he read a newspaper account that he was engaged to marry Milo Abercrombie. Brushing it off, Koehler curtly told the press, "Some error," while Abercrombie did not take it so lightly. "I have been deeply humiliated", she told reporters, her eyes "wet with tears". "This is a most unkind blow of fate. I cannot possibly understand how this false rumor got about." Two years later, Koehler married Matilda Pell, the ex-wife of U.S. Congressman Herbert Pell (D-NY) and mother of future United States Senator Claiborne Pell (D-RI). In a bitter child visitation court battle in 1927 that went all the way to the California Court of Appeals, Abercrombie lost custody of her children with Swenson to him, after making baseless accusations that he had molested their four-year old daughter, Cecelia. The appellate court excoriated Abercrombie, "[I]in furtherance of a manifest determination to prevent him from ever seeing the children again, under any circumstances, she was instrumental in inspiring and promoting a scheme directly involving one of the children which had for its obvious purpose the ruination of respondent's character as a man, the bringing about of his complete disgrace as a naval officer, and the destruction of the love and affection which his children had theretofore manifested toward him." Swenson v. Swenson" (1929) 101 Cal.App. 440. In 1929, Lyman Swenson married Loretta B. Bruner (1897-1979). His son, Lyman K. Swenson Jr. ("Robert") (1923-2016) was also a US Naval officer.
 Passage 3:In 1903, the party split into Bolsheviks led by Vladimir Lenin and Mensheviks led by Julius Martov and Lunacharsky sided with the former. In 1907, he attended the International Socialist Congress, held in Stuttgart. When the Bolsheviks in turn split into Lenin's supporters and Alexander Bogdanov's followers in 1908, Lunacharsky supported his brother-in-law Bogdanov in setting up Vpered. Like many contemporary socialists (including Bogdanov), Lunacharsky was influenced by the empirio-criticism philosophy of Ernst Mach and Avenarius. Lenin opposed Machism as a form of subjective idealism and strongly criticised its proponents in his book Materialism and Empirio-criticism (1908). In 1909, Lunacharsky joined Bogdanov and Gorky at the latter's villa on the island of Capri, where they started a school for Russian socialist workers. In 1910, Bogdanov, Lunacharsky, Mikhail Pokrovsky and their supporters moved the school to Bologna, where they continued teaching classes through 1911. In 1913, Lunacharsky moved to Paris, where he started his own Circle of Proletarian Culture.

Output:
3