input: Following the first successful kidney transplant in 1953, in the United States, Barnard performed the second kidney transplant in South Africa in October 1967, the first being done in Johannesburg the previous year. On 23 January 1964, James Hardy at the University of Mississippi Medical Center in Jackson, Mississippi, performed the world's first heart transplant and world's first cardiac xenotransplant by transplanting the heart of a chimpanzee into a desperately ill and dying man. This heart did beat in the patient's chest for approximately 60 to 90 minutes. The patient, Boyd Rush, died without ever regaining consciousness. Barnard had experimentally transplanted forty-eight hearts into dogs, which was about a fifth the number that Adrian Kantrowitz had performed at Maimonides Medical Center in New York and about a sixth the number Norman Shumway had performed at Stanford University in California. Barnard had no dogs which had survived longer than ten days, unlike Kantrowitz and Shumway who had had dogs survive for more than a year. With the availability of new breakthroughs introduced by several pioneers, also including Richard Lower at the Medical College of Virginia, several surgical teams were in a position to prepare for a human heart transplant. Barnard had a patient willing to undergo the procedure, but as with other surgeons, he needed a suitable donor. During the Apartheid era in South Africa, non-white persons and citizens were not given equal opportunities in the medical professions. At Groote Schuur Hospital, Hamilton Naki was an informally taught surgeon. He started out as a gardener and cleaner. One day he was asked to help out with an experiment on a giraffe. From this modest beginning, Naki became principal lab technician and taught hundreds of surgeons, and assisted with Barnard's organ transplant program. Barnard said, "Hamilton Naki had better technical skills than I did. He was a better craftsman than me, especially when it came to stitching, and had very good hands in the theatre". A popular myth, propagated principally by a widely discredited documentary film called Hidden Heart and an erroneous newspaper article , maintains incorrectly that Naki was present during the Washkansky transplant.

Answer this question "Were these controversial?"
output:

input: NBC kept Letterman under contract to try him in a different time slot. Late Night with David Letterman debuted February 1, 1982; the first guest on the first show was Bill Murray. Murray later went on to become one of Letterman's most recurrent guests, guesting on the show's 30th anniversary episode, which aired January 31, 2012 and on the very last show, which aired May 20, 2015. The show ran Monday through Thursday at 12:30 a.m. Eastern Time, immediately following The Tonight Show Starring Johnny Carson (a Friday night broadcast was added in June 1987). It was seen as being edgy and unpredictable, and soon developed a cult following (particularly among college students). Letterman's reputation as an acerbic interviewer was borne out in verbal sparring matches with Cher (who even called him an asshole on the show), Shirley MacLaine, Charles Grodin, and Madonna. The show also featured comedy segments and running characters, in a style heavily influenced by the 1950s and 1960s programs of Steve Allen. The show often featured quirky, genre-mocking regular features, including "Stupid Pet Tricks" (which had its origins on Letterman's morning show), Stupid Human Tricks, dropping various objects off the roof of a five-story building, demonstrations of unorthodox clothing (such as suits made of Alka-Seltzer, Velcro and suet), a recurring Top 10 list, the Monkey-Cam (and the Audience Cam), a facetious letter-answering segment, several "Film[s] by My Dog Bob" in which a camera was mounted on Letterman's own dog (often with comic results) and Small Town News, all of which would eventually move with Letterman to CBS. Other memorable moments included Letterman using a bullhorn to interrupt a live interview on The Today Show, announcing that he was the NBC News president and that he was not wearing any pants; walking across the hall to Studio 6B, at the time the news studio for WNBC-TV, and interrupting Al Roker's weather segments during Live at Five; and staging "elevator races", complete with commentary by NBC Sports' Bob Costas. In one infamous appearance, in 1982, Andy Kaufman (who was already wearing a neck brace) appeared with professional wrestler Jerry Lawler, who slapped and knocked the comedian to the ground (though Lawler and Kaufman's friend Bob Zmuda later revealed that the event was staged).

Answer this question "How many years did late night run?"
output: the very last show, which aired May 20, 2015.

input: Together with Oliver Tambo, Mbeki left London for Lusaka in April 1971 to take up the position of assistant secretary of the ANC's Revolutionary Council (RC). This was the first time in nine years that Mbeki was setting foot on African soil. The aim of the RC at this time was to bridge an ever-widening gap between the ANC in exile and the people back home. In Lusaka, Mbeki was housed in a secret location in Makeni, south-west of the city. Later, Mbeki moved over to work in the ANC's propaganda section. But he continued to attend RC meetings. Four months after his arrival in Lusaka, Mbeki travelled to Beichlingen to deliver a speech on behalf of the ANC's Executive Committee at the YSS summer school. This was a turning point in Mbeki's life as it was the first time he spoke on behalf of the ANC as opposed to the ANC Youth League. In December 1972, Mbeki joined Tambo at Heathrow Airport to meet Mangosuthu Buthelezi to discuss mass resistance to apartheid. Mbeki is credited with facilitating the establishment of Inkatha - it was his responsibility to nurture the relationship between Buthelezi and the ANC. Mbeki was deployed to Botswana in 1973 to facilitate the development of an internal underground. Mbeki's life took a significant turn on 23 November 1974 when he married Zanele Dlamini. The wedding ceremony took place at Farnham Castle, the residence of Zanele's sister Edith and her husband, Wilfred Grenville-Grey. Adelaide Tambo and Mendi Msimang stood in loco-parentis for Mbeki while Essop Pahad was Mbeki's best man. The wedding, according to ANC rules, had to be approved by the organisation - a rule that applied to all permanently deployed members of the ANC.

Answer this question "When did he arrive in Lusaka?"
output:
Mbeki left London for Lusaka in April 1971