With no explanation, label text_A→text_B with either "not_related" or "related".
text_A: Doctor Who has been played by multiple actors
text_B: Doctor Who is a British science-fiction television programme produced by the BBC since 1963 .. British. British television science fiction. science-fiction television. science fiction on television. BBC. BBC. Doctor Who. Doctor Who ( film ). The programme depicts the adventures of a Time Lord called `` The Doctor '' , an extraterrestrial being from the planet Gallifrey .. Time Lord. Time Lord. The Doctor. The Doctor ( Doctor Who ). extraterrestrial being. Extraterrestrial life. Gallifrey. Gallifrey. He explores the universe in a time-travelling space ship called the TARDIS .. time-travelling. time-travelling. TARDIS. TARDIS. Its exterior appears as a blue British police box , which was a common sight in Britain in 1963 when the series first aired .. British. British television science fiction. police box. police box. Accompanied by a number of companions , the Doctor combats a variety of foes , while working to save civilisations and help people in need .. a number of companions. Companion ( Doctor Who ). a variety of foes. List of Doctor Who villains. The show is a significant part of British popular culture , and elsewhere it has gained a cult following .. British. British television science fiction. British popular culture. British popular culture. cult following. cult following. It has influenced generations of British television professionals , many of whom grew up watching the series .. British. British television science fiction. The programme originally ran from 1963 to 1989 .. There was an unsuccessful attempt to revive regular production in 1996 with a backdoor pilot , in the form of a television film titled Doctor Who .. backdoor pilot. Television pilot#Backdoor pilot. Doctor Who. Doctor Who ( film ). The programme was relaunched in 2005 , and since then has been produced in-house by BBC Wales in Cardiff .. BBC. BBC. relaunched in 2005. History of Doctor Who#2000s. BBC Wales. BBC Cymru Wales. Cardiff. Cardiff. Doctor Who has also spawned numerous spin-offs , including comic books , films , novels , audio dramas , and the television series Torchwood -LRB- 2006 -- 2011 -RRB- , The Sarah Jane Adventures -LRB- 2007 -- 2011 -RRB- , K-9 -LRB- 2009 -- 2010 -RRB- , and Class '' -LRB- 2016-present -RRB- , and has been the subject of many parodies and references in popular culture .. Torchwood. Torchwood. The Sarah Jane Adventures. The Sarah Jane Adventures. K-9. K-9 ( TV series ). Class. Class ( 2016 TV series ). Doctor Who. Doctor Who ( film ). spin-offs. Doctor Who spin-offs. parodies and references. List of Doctor Who parodies. Twelve actors have headlined the series as the Doctor .. The transition from one actor to another is written into the plot of the show with the concept of regeneration into a new incarnation -- an idea introduced in 1966 to allow the show to continue after the departure of original lead William Hartnell who was becoming very ill at the time .. concept of regeneration. Regeneration ( Doctor Who ). incarnation. incarnation. William Hartnell. William Hartnell. The concept is that this is a Time Lord trait through which the character of the Doctor takes on a new body and personality to recover from a severe injury or anything that would otherwise kill a normal person .. Time Lord. Time Lord. Each actor 's portrayal differs , but all represent stages in the life of the same character and form a single narrative .. The time-travelling feature of the plot means that different incarnations of the Doctor occasionally meet .. time-travelling. time-travelling. The current lead , Peter Capaldi , took on the role after Matt Smith 's exit in the 2013 Christmas special `` The Time of the Doctor '' .. Peter Capaldi. Peter Capaldi. Matt Smith. Matt Smith ( actor ). The Time of the Doctor. The Time of the Doctor. In 2017 , Capaldi confirmed he would be leaving at the end of the tenth series , with his final appearance being the 2017 Christmas Special .
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