Task: Question Answering
Input (English): Passage: The Beatles' 1, a compilation album of the band's British and American number-one hits, was released on 13 November 2000. It became the fastest-selling album of all time, with 3.6 million sold in its first week and 13 million within a month. It topped albums charts in at least 28 countries. As of April 2009, the compilation had sold 31 million copies globally, and is the best-selling album of that decade in the United States.Harrison died from metastatic lung cancer in November 2001. McCartney and Starr were among the musicians who performed at the Concert for George, organised by Eric Clapton and Harrison's widow, Olivia. The tribute event took place at the Royal Albert Hall on the first anniversary of Harrison's death.In 2003, Let It Be... Naked, a reconceived version of the Let It Be album, with McCartney supervising production, was released. One of the main differences from the Spector-produced version was the omission of the original string arrangements. It was a top ten hit in both Britain and America. The US album configurations from 1964 to 1965 were released as box sets in 2004 and 2006; The Capitol Albums, Volume 1 and Volume 2 included both stereo and mono versions based on the mixes that were prepared for vinyl at the time of the music's original American release.As a soundtrack for Cirque du Soleil's Las Vegas Beatles stage revue, Love, George Martin and his son Giles remixed and blended 130 of the band's recordings to create what Martin called "a way of re-living the whole Beatles musical lifespan in a very condensed period". The show premiered in June 2006, and the Love album was released that November. In April 2009, Starr performed three songs with McCartney at a benefit concert held at New York's Radio City Music Hall and organised by McCartney.
On 9 September 2009, the Beatles' entire back catalogue was reissued following an extensive digital remastering process that lasted four years. Stereo editions of all twelve original UK studio albums, along with Magical Mystery Tour and the Past Masters compilation, were released on compact disc both individually and as a box set. A second collection, The Beatles in Mono, included remastered versions of every Beatles album released in true mono along with the original 1965 stereo mixes of Help! and Rubber Soul (both of which Martin had remixed for the 1987 editions). The Beatles: Rock Band, a music video game in the Rock Band series, was issued on the same day. In December 2009, the band's catalogue was officially released in FLAC and MP3 format in a limited edition of 30,000 USB flash drives. 
Question: What formats was the catalogue of the band that has the fastest-selling album of all time release in in December 2009?
Output (English): FLAC.