In digital logic, a don't-care term is an input-sequence (a series of bits) to a function that the designer does not care about, usually because that input would never happen, or because differences in that input would not result in any changes to the output. By considering these don't-care inputs, designers can potentially minimize their function much more so than if the don't-care inputs were taken to have an output of all 0 or all 1. Examples of don't-care terms are the binary values 1010 through 1111 (10 through 15 in decimal) for a function that takes a BCD value, because a BCD value never takes on values from 1010 to 1111. Don't-care terms are important to consider in minimizing, using Karnaugh maps and the Quine–McCluskey algorithm.

"Don't care" may also refer to an unknown value in a multi-valued logic system, in which case it may also be called an X value. In the Verilog hardware description language such values are denoted by the letter "X". In the VHDL hardware description language such values are denoted (in the standard logic package) by the letter "X" (forced unknown) or the letter "W" (weak unknown).

Demetria Devonne "Demi" Lovato (born August 20, 1992) is an American singer-songwriter, musician, and actress. Her earliest roles included Angela on Barney & Friends, before she became better known for her starring roles in the Camp Rock movies, as Sonny Munroe in the Disney sitcom Sonny with a Chance, and as the star of the 2009 movie Princess Protection Program. She is also involved in philanthropic activities through charity work and various social and environmental causes.

As a solo musical artist, Lovato released her debut album Don't Forget on September 23, 2008. The album debuted at number two on the Billboard 200 selling 89,000 copies in the first week. It has since shipped over 500,000 copies, earning a gold certification in the United States. Lovato released her second album, Here We Go Again, on July 21, 2009. The album debuted at number one on the Billboard 200, selling 108,000 copies in the first week. Her third studio album, Unbroken, was released on September 20, 2011 and peaked at number four on the Billboard 200. She is working on her fourth studio album.

Cher Lloyd (born 28 July 1993) is an English recording artist. Lloyd rose to fame when she finished fourth in the seventh series of The X Factor. Shortly afterwards, Lloyd was signed by Simon Cowell to Sony Music subsidiary Syco Music.

Cher Lloyd's debut single "Swagger Jagger" was released in June 2011. Despite receiving negative reviews, the single entered at number one on the UK Singles Chart and number two on the Irish Singles Chart. Her second single "With Ur Love" was released on 31 October, featuring Mike Posner, and peaked at number four in the UK, and number five in Ireland, preceding her debut album Sticks + Stones, which peaked at number four in the UK Albums Chart and number seven on the Irish Albums Chart.

Cher Lloyd used to live in Malvern with her parents Darren and Dina, and three younger siblings brother Josh, and sisters Sophie and Rosie. Lloyd attended Dyson Perrins CE Sports College, where she studied performing arts. She also attended theatre arts school Stagecoach.

Lloyd had previously auditioned for The X Factor twice before (when the minimum age was lower) singing ballads, but did not make it through. Lloyd has previously performed at holiday camps and said she gets a mixed reaction to her music, but was a big hit with x-factor judge at the time Cheryl Cole. She remarked on their similarity and Cheryl went on to support her throughout the show. She auditioned singing the Keri Hilson version of "Turn My Swag On". At bootcamp she sang a rap version of "Viva La Vida" adding lyrics she claimed to have written herself, but this was disputed and reports claimed she took them from a song by rapper Swizz Beatz. At the judges' houses she performed "Cooler Than Me" but suffered from tonsillitis and was unable to complete her song. She was given a second chance, but broke down sobbing and could not complete the song. Despite this, she was still picked as one of the final three girls by mentor Cheryl Cole.