Instructions: 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: Which is the most populous city that the 12th Reconnaissance Squadron was assigned to on CAA Route 18? Passage 1:"Celebrate" was written and produced by R. Kelly and is the last song that Whitney Houston recorded; it is a duet between Houston and R&B/pop singer Jordin Sparks. It was released as the lead single from the soundtrack album  on June 5, 2012. It was officially released on June 5, 2012 for digital download on iTunes and Amazon. The song made its US radio premiere on On Air with Ryan Seacrest on May 21, 2012. For the week June 16, 2012, "Celebrate" debuted at number 34 on the US Adult R&B Airplay chart, having amassed 45 spins for that week ending. During that same week, "Celebrate" also debuted at number 84 on the US Hot R&B/Hip-Hop Songs chart, and has since peaked at number 80. The music video for "Celebrate" was filmed on May 30, 2012. The video was shot over two days and a preview premiered on Entertainment Tonight on June 4, 2012. The music video made its world premiere on BET's 106 & Park on June 27, 2012.
 Passage 2:In 1934, the 12th took part when the Army was given responsibility for flying the mail after President Franklin Roosevelt cancelled all civilian contracts because of alleged rate-fixing by the airlines. 12th pilots were assigned to the difficult and dangerous CAA Route 18, from Salt Lake City, Utah to Oakland, California, via Elko, Nevada, and Sacramento, California. The aircraft they flew were primarily Douglas Y1B-7 bombers. On 1 June 1937, the 12th Observation Squadron left Texas to operate with the 7th Cavalry Brigade, the mechanized forerunner of the First Armored Division, at Fort Knox, Kentucky. While stationed at Fort Knox, the squadron participated in field maneuvers with the mechanized cavalry near Fort Oglethorpe, Georgia, and at Fort Riley, Kansas, in 1938; in the First Army maneuvers at Plattsburg, New York in 1939; and in the Third Army maneuvers in Louisiana in 1940. In the summer of 1940, the squadron was the first to be attached to an armored division – the First – and on 2 December, a base detachment was formed at For. Knox to manage Goodman Field, a new and modern airfield still under construction. Captain Robert M. Lee, commanding officer of the 12th, was also detachment commander. Along with the First Armored Division, the 12th Squadron played an active role in the Carolina and Louisiana Maneuvers from July to December 1941. After those maneuvers, the 12th returned to the recently completed Godman Field, where the unit supplied a cadre to organize the Headquarters Squadron of the 73d Observation Group.
 Passage 3:"Hands on Me" is a song on Vanessa Carlton's third studio album, Heroes & Thieves (2007), and is the album's second single. According to the website FMQB.com, it was released to mainstream contemporary hit radio in the United States on February 19, 2008 (see 2008 in music). It was mentioned as a possible choice for the second single in a June 2007 article in Entertainment Weekly, which wrote that it "sounded tailor-made for a rom-com trailer coming soon to a theater near you." Irv Gotti, the head of Carlton's label, The Inc. Records, was quoted as saying that the song reminded him of the 1985 film The Breakfast Club.

Output:
2