Task: Question Answering
Input (English): Passage: Radiohead finished recording their eighth album, The King of Limbs, in January 2011. Following the protracted recording and more conventional rock instrumentation of In Rainbows, Radiohead developed The King of Limbs by sampling and looping their recordings with turntables. Radiohead announced the album on Valentine's Day and released it as a download on 18 February 2011 through their website. It was followed by a retail release on CD and vinyl formats in March on XL, and a special "newspaper album" edition in May. The King of Limbs sold an estimated 300,000 to 400,000 copies through Radiohead's website; the retail edition debuted at number six on the US Billboard 200 and number seven on the UK Albums Chart. It was nominated for five categories in the 54th Grammy Awards. Two tracks not included on The King of Limbs, "Supercollider" and "The Butcher", were released as a double A-side single for Record Store Day in April. A compilation of King of Limbs remixes by various artists, TKOL RMX 1234567, was released in September.To perform the rhythmically complex King of Limbs material live, Radiohead enlisted a second drummer, Clive Deamer, who had worked with Portishead and Get the Blessing. Deamer has joined Radiohead on subsequent tours. In June, Radiohead played a surprise performance on the Park stage at the 2011 Glastonbury Festival, performing songs from The King of Limbs for the first time. With Deamer, Radiohead recorded The King of Limbs: Live from the Basement, released online in August 2011. It was also broadcast by international BBC channels and released on DVD and Blu-ray in January 2012. The performance included two new songs, "The Daily Mail" and "Staircase", released as a double A-side download single in December 2011. In February 2012, they began their first extended North American tour in four years, including dates in the United States, Canada and Mexico. On tour, they recorded material at Jack White's studio Third Man Records, but discarded the recordings.On 16 June 2012, an hour before gates were due to open at Toronto's Downsview Park for the final concert of Radiohead's North American tour, the roof of the venue's temporary stage collapsed, killing drum technician Scott Johnson and injuring three other members of Radiohead's road crew. After rescheduling the tour, Radiohead paid tribute to Johnson at their next concert, in Nîmes, France, in July. In June 2013, Live Nation Canada Inc, two other organisations and an engineer were charged with 13 charges under Ontario health and safety laws. In September 2017, after several delays, the case was dropped under the Jordan ruling, which sets strict timelines on trials. Radiohead released a statement condemning the decision. A 2019 inquest returned a verdict of accidental death. 
Question: What were the names of the two new songs released as a double A-side download single in December 2011?
Output (English): The Daily Mail.