Question: When did the 2008 Olympic torch arrive in the birthplace of Kang Chol-hwan?

full_context: Document 1: Mangyongdae Funfair: The Mangyongdae Funfair is an amusement park located in Mangyongdae-guyok, 12 kilometers from Pyongyang, North Korea. It has an area of 70 hectares including a funfair and wading pool. In fall, 2011 the funfair was reported to have little or no Korean patronage. It has been alleged that there is a lack of genuine customers with many visitors being bussed in to the attraction. It had a roller coaster, which, while operational, was in poor repair. There is a merry-go-round and a ridable miniature railway.
Document 2: Chinese characters: After Kim Jong Il, the second ruler of North Korea, died in December 2011, Kim Jong Un stepped up and began mandating the use of Hanja as a source of definition for the Korean language. Currently, it is said that North Korea teaches around 3,000 Hanja characters to North Korean students, and in some cases, the characters appear within advertisements and newspapers. However, it is also said that the authorities implore students not to use the characters in public. Due to North Korea's strict isolationism, accurate reports about hanja use in North Korea are hard to obtain.
Document 3: 2008 Summer Olympics torch relay: In many cities along the North American and European route, the torch relay was protested by advocates of Tibetan independence, animal rights, and legal online gambling, and people protesting against China's human rights record, resulting in confrontations at a few of the relay locations. These protests, which ranged from hundreds of people in San Francisco, to effectively none in Pyongyang, forced the path of the torch relay to be changed or shortened on a number of occasions. The torch was extinguished by Chinese security officials several times during the Paris leg for security reasons, and once in protest in Paris.
Document 4: Côn Đảo Prison: Côn Đảo Prison (), also Côn Sơn Prison, is a prison on Côn Sơn Island (also known as Côn Lôn) the largest island of the Côn Đảo archipelago in southern Vietnam (today it is in Bà Rịa–Vũng Tàu Province. The prison was built in 1861 by the French colonists to jail those considered especially dangerous to the colonial government. Many of the high-ranking leaders of Vietnam were detained here. It is ranked a special historical relic of national importance by the government of Vietnam. The most famous site in this prison are the "tiger cages" (vi:"chuồng cọp"). The French tiger cages cover an area of 5.475 m, within which each cell occupies 1.408 m, solariums occupy 1.873 m, and other spaces occupy 2.194 m. The prison includes 120 cells.
Document 5: 2018 Winter Olympics torch relay: The 2018 Winter Olympics torch relay began 24 October 2017 and ended on 9 February 2018, in advance of the 2018 Winter Olympics. After being lit in Olympia, Greece, the torch traveled to Athens on 31 October. The torch began its Korean journey on 1 November, visiting all Regions of Korea. The Korean leg began in Incheon: the torch travelled across the country for 101 days. 7,500 relay runners participated in the torch relay over a distance of 2,017 km. The torchbearers each carried the flame for 200 metres. The relay ended in Pyeongchang's Olympic Stadium, the main venue of the 2018 Olympics. The final torch was lit by figure skater Yuna Kim.
Document 6: 2008 Summer Olympics torch relay: Thailand: The April 18 relay through Bangkok was the Olympic flame's first visit to Thailand. The relay covered just over 10 km, and included Bangkok's Chinatown. The torch was carried past Democracy Monument, Chitralada Palace and a number of other city landmarks. M.R. Narisa Chakrabongse, Green World Foundation (GWF) chairwoman, withdrew from the torch-running ceremony, protesting against China's actions in Tibet. Several hundred protesters were present, along with Olympic supporters. Thai authorities threatened to arrest foreign protesters and ban them from future entry into Thailand. A coalition of Thai human rights groups announced that it would organise a "small demonstration" during the relay, and several hundred people did indeed take part in protests, facing Beijing supporters. Intended torchbearer Mom Rajawongse Narissara Chakrabongse boycotted the relay, to protest against China's actions in Tibet. In Bangkok, students told the media that the Chinese Embassy provided them with transportation and gave them shirts to wear.
Document 7: 2008 Summer Olympics torch relay: North Korea: The event was held in Pyongyang on April 28. It was the first time that the Olympic torch has traveled to North Korea. A crowd of thousands waving pink paper flowers and small flags with the Beijing Olympics logo were organized by the authoritarian regime watched the beginning of the relay in Pyongyang, some waving Chinese flags. The event was presided over by the head of the country's parliament, Kim Yong Nam. The North, an ally of China, has been critical of disruptions to the torch relay elsewhere and has supported Beijing in its actions against protests in Tibet. Kim passed the torch to the first runner Pak Du Ik, who played on North Korea's 1966 World Cup soccer team, as he began the 19-kilometre route through Pyongyang. The relay began from the large sculpted flame of the obelisk of the Juche Tower, which commemorates the national ideology of Juche, or "self-reliance", created by the country's late founding President Kim Il Sung, father of leader Kim Jong Il, who did not attend.
Document 8: With the Century: Reminiscences: With the Century () is the autobiography of Kim Il-sung, founder and president of North Korea. The memoirs, written in 1992 and published in eight volumes, retell Kim's life story through his childhood to the time of Korean resistance. Initially, a total of 30 volumes were planned but Kim Il-sung died in 1994 after just six volumes; the seventh and eight volumes were published posthumously. The work reveals early influences of religious and literary ideas on Kim's thinking. An important part of North Korean literature, "With the Century" is held as a valuable if somewhat unreliable insight into the nation's modern history under late colonial Korea. The book is considered one of a few North Korean primary sources widely available in the West and as notable research material for North Korean studies.
Document 9: Rim Ju-song: At the time when he was selected, he was living in Beijing. By the time North Korea received clearance to compete in London, it was "too late to qualify for most events, but swimming was an exception". Thus North Korea's representative would have to be a swimmer. Rim, who did not know how to swim, began to learn the crawl stroke in April 2012, reportedly with great difficulty at first, and the breaststroke in May.
Document 10: North Korea at the 2008 Summer Olympics: North Korea (Democratic People's Republic of Korea) competed in the 2008 Summer Olympics, held in Beijing, People's Republic of China from August 8 to August 24, 2008. The country sent 63 athletes, competing in 11 sports.
Document 11: Hyon Chol-hae: During the Korean War, Hyon served as Kim Il-sung's bodyguard, a role which gave him "a place in North Korea's revolutionary history". He was director of the General Logistics Department of the Korean People's Army from 1986 to 1995, when he was appointed deputy director of the General Political Department, becoming one of the senior most members of the North Korean military and political leadership. He has been described as being in "close proximity" to Kim Jong-il, and as reporting directly to him. It had been suggested that, following Kim Jong-il's death, he may have taken part in a military council leadership of the country. He was transferred to director of the Standing Bureau of the National Defence Commission. He has been a member of the Central Committee of the Workers' Party of Korea since 1991.
Document 12: 2008 Summer Olympics torch relay: After being lit at the birthplace of the Olympic Games in Olympia, Greece on March 24, the torch traveled to the Panathinaiko Stadium in Athens, and then to Beijing, arriving on March 31. From Beijing, the torch was following a route passing through six continents. The torch has visited cities along the Silk Road, symbolizing ancient links between China and the rest of the world. The relay also included an ascent with the flame to the top of Mount Everest on the border of Nepal and Tibet, China from the Chinese side, which was closed specially for the event.
Document 13: The Aquariums of Pyongyang: The Aquariums of Pyongyang, by Kang Chol-hwan and Pierre Rigoulot, is an account of the imprisonment of Kang Chol-Hwan and his family in the Yodok concentration camp in North Korea.
Document 14: The Gulag Archipelago: The Gulag Archipelago (Russian: Архипелаг ГУЛАГ, Arkhipelag GULAG) is a book by Aleksandr Solzhenitsyn about the Soviet forced labor camp system. The three - volume book is a narrative relying on eyewitness testimony and primary research material, as well as the author's own experiences as a prisoner in a gulag labor camp. Written between 1958 and 1968, it was published in the West in 1973 and, thereafter, it was circulated in samizdat (underground publication) form in the Soviet Union until its appearance in the Russian literary journal, Novy Mir, in 1989, in which a third of the work was published in three issues.
Document 15: 2008 Summer Olympics torch relay: Kazakhstan: The first torchbearer in Almaty, where the Olympic torch arrived for the first time ever on April 2, was the President of Kazakhstan Nursultan Nazarbaev. The route ran 20 km from Medeo stadium to Astana Square. There were reports that Uighur activists were arrested and some were deported back to China.
ground_truth: April 28
sub_queries: Kang Chol-hwan >> place of birth Answer: Pyongyang
When did the torch arrive in Pyongyang ? Answer: April 28