Question: Which building has more floors, Americas Tower or 919 Third Avenue?
Context: 14th Street was a local station on New York's demolished IRT Third Avenue Line.  It had two levels.  The lower level was served by local trains and had two tracks and two side platforms.  It was built first.  The upper level was built as part of the Dual Contracts and had one track that bypassed the station and served express trains.  In 1924, the Brooklyn–Manhattan Transit Corporation built the 14th Street-Eastern District Line Subway below the station, which included the Third Avenue subway station.  Although this station was located above the Third Avenue BMT subway station on what is today known as the BMT Canarsie Line, the two stations were never connected.  This station closed on May 12, 1955, with the ending of all service on the Third Avenue El south of 149th Street. 129th Street was a massive station on the IRT Third Avenue Line, shared by trains of both the Third Avenue Line and IRT Second Avenue Line in the New York City Subway system.  The next stop to the north was 133rd Street for the main line and Willis Avenue for the Willis Avenue spur, both of which were across a swing bridge above the Harlem River in The Bronx.  The next stop to the south was 125th Street−Third Avenue for Third Avenue Line trains and 125th Street−Second Avenue for Second Avenue Line trains. The Third Avenue Bridge carries southbound road traffic on Third Avenue over the Harlem River, connecting the boroughs of Manhattan and the Bronx in New York City.  It once carried southbound New York State Route 1A.  The Third Avenue Bridge carries traffic south from Third Avenue, East 135th Street, Bruckner Boulevard, and Lincoln Avenue in the Bronx, to East 128th Street, East 129th Street, Lexington Avenue, and the Harlem River Drive in Manhattan, traveling over the Metro-North Railroad Oak Point Link, the Harlem River, and Harlem River Drive.  The bridge was formerly bidirectional, but converted to one-way operation southbound on August 5, 1941 on the same day the Willis Avenue Bridge was similarly converted to one-way northbound. 919 Third Avenue is an office building in New York City, built in 1971, and is located at the intersection of Third Avenue and East 55th Street in Midtown Manhattan.  The building is 615 feet (188 meters) tall with 47 floors.  The building was designed by Skidmore, Owings and Merrill. City Hall was a station on the IRT Second Avenue Line, which also served trains of the IRT Third Avenue Line.  It lay along Park Row, south of the Manhattan Municipal Building.  It had 2 levels.  The lower level served Third Avenue trains and had two tracks with two side platforms for exiting passengers, and a center island platform for entering passengers.  The upper level served Second Avenue trains and had two tracks and two side platforms for exiting passengers, and one island platform for entering passengers.  Second Avenue trains served the station until June 13, 1942, and Third Avenue trains served the station until December 31, 1953.  The next stop to the north was Chatham Square for all trains. Chatham Square was a station on the demolished IRT Third Avenue Line.  It had two levels.  The lower level had two tracks and one island platform that served trains of both the IRT Second Avenue Line and IRT Third Avenue Line.  The upper level had three tracks and two island platforms that served trains of both lines going to and from City Hall.  Second Avenue trains served the station until June 13, 1942, and City Hall Spur trains served the station until December 31, 1953.  This station closed entirely on May 12, 1955, with the ending of all service on the Third Avenue El south of 149th Street. 99th Street was a local station on the demolished IRT Third Avenue Line in New York City.  The station was originally built by the Manhattan Railway Company on December 30, 1878, and later had two levels.  The lower level serving local trains was built first, and had two tracks and two side platforms.  The upper level, built as part of the Dual Contracts had one track that bypassed the station and served express trains.  This station closed on May 12, 1955, with the ending of all service on the Third Avenue El south of 149th Street.  South of the station were connecting tracks to the 98th Street Yard.  The station was also located next to Substation 7 an old IRT substation designed not only in order to electrify the Third Avenue Line, but the Second and Ninth Avenue elevated lines as well.  Later it even served as a power source for the IRT Lexington Avenue Line from 1918 until the 1970s.  The substation is still owned by the MTA and has been listed on the National Register of Historic Places since February 9, 2006. Americas Tower, also known as 1177 Avenue of the Americas, is a 50-story, 692-foot (211 m) office tower in Midtown Manhattan, New York City, standing at West 45th Street. The Fifth Avenue Line, also called the Fifth Avenue Elevated or Fifth Avenue-Bay Ridge Line, was an elevated rail line in Brooklyn, New York City, United States.  It ran above Hudson Avenue, Flatbush Avenue, Fifth Avenue, 38th Street, and Third Avenue from Downtown Brooklyn south to Bay Ridge.  The portion on Third Avenue was called the Third Avenue Elevated to distinguish service from the West End Elevated. The Haffen Building is a historic New York City landmark constructed in 1901-1902 in the neighborhood of North New York (now known as Mott Haven), Bronx, New York.  The building is located at 2804 Third Avenue, also addressed as 507 Willis Avenue, in the middle of a triangular block between 148th Street, 147th Street, Third Avenue, and Willis Avenue, within the Hub business district.  It was inspired by the economic growth and upper middle-class status that was prevalent in the area during the period.  When constructed, the Third Avenue and Second Avenue elevated train line stopped at 149th Street, a station in front of it.
Answer: Americas Tower