Question: When did the Olympic torch arrive in the city where the Ryugyong Hotel is located?

full_context: Document 1: 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 2: Hanoi: Hanoi has experienced a rapid construction boom recently. Skyscrapers, popping up in new urban areas, have dramatically changed the cityscape and have formed a modern skyline outside the old city. In 2015, Hanoi is ranked # 39 by Emporis in the list of world cities with most skyscrapers over 100 m; its two tallest buildings are Hanoi Landmark 72 Tower (336 m, second tallest in Vietnam after Ho Chi Minh City's Landmark 81 and third tallest in south-east Asia after Malaysia's Petronas Twin Towers) and Hanoi Lotte Center (272 m, also, third tallest in Vietnam).
Document 3: 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 4: 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 5: Kim Il-sung Square: Kim Il-sung Square is a large city square in the Central District of Pyongyang, North Korea, and is named after the country's founding leader, Kim Il-sung. The square was constructed in 1954 according to a master plan for reconstructing the capital after the destruction of the Korean War. It was opened in August 1954. The square is located on the foot of the Namsan Hill, west bank of the Taedong River, directly opposite the "Juche" Tower on the other side of the river. It is the 37th largest square in the world, having an area of about 75,000 square metres (807,293 square feet) which can accommodate a rally of more than 100,000 people. The square has a great cultural significance, as it is a common gathering place for rallies, dances and military parades and is often featured in media concerning North Korea.
Document 6: List of tallest buildings and structures: The world's tallest artificial structure is the 829.8 m (2,722 ft) tall Burj Khalifa in Dubai (of the United Arab Emirates). The building gained the official title of ``Tallest Building in the World ''and the tallest self supported structure at its opening on January 9, 2010. The second tallest self - supporting structure and the tallest tower is the Tokyo Skytree. The tallest guyed structure is the KVLY - TV mast.
Document 7: List of tallest buildings and structures: The world's tallest artificial structure is the 829.8 - metre - tall (2,722 ft) Burj Khalifa in Dubai (of the United Arab Emirates). The building gained the official title of ``Tallest Building in the World ''and the tallest self - supported structure at its opening on January 9, 2010. The second - tallest self - supporting structure and the tallest tower is the Tokyo Skytree. The tallest guyed structure is the KVLY - TV mast. Breetsky was the third building, which was surpassed by Tokyo in 1987.
Document 8: 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.
Document 9: Ryugyong Hotel: The Ryugyong Hotel (; sometimes spelled as Ryu-Gyong Hotel), or Yu-Kyung Hotel, is an unfinished 105-story, pyramid-shaped skyscraper in Pyongyang, North Korea. Its name ("capital of willows") is also one of the historical names for Pyongyang. The building is also known as the 105 Building, a reference to its number of floors. The building has been planned as a mixed-use development, which would include a hotel. The building is currently listed by Guinness World Records as being the tallest unoccupied building in the world.
Document 10: 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 11: 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 12: Hyperion Tower: The Hyperion Tower (Korean: 하이페리온 타워), also known as the Mok-dong Hyperion Towers, is a group of three buildings located in the Yangcheon-gu district of Seoul, South Korea, completed in 2003. The tallest of which, Tower A, is 69 storeys and 256 metres (840 feet) high, making it the second tallest building in Seoul and the world's 214th tallest building. The towers are used as residential housing. Tower A is the world's 19th tallest residential building. Below the building is the Hyundai Department store, a chain of high end department stores in South Korea. At the time of its completion, the building was the tallest in the country but was surpassed by Samsung Tower Palace 3 – Tower G in 2004.
Document 13: Potonggang-guyok: Potonggang-guyok is one of the 19 districts, or guyok, of Pyongyang, North Korea. It is most famous as the location of the Ryugyong Hotel. It is named after the Pothong River (literally "the simple river"), which serves as the district's border on all sides. It is bordered to the north by Hyongjesan-guyok, to the east by Sosong and Moranbong-guyoks, to the south by Pyongchon and Chung-guyoks, and to the west by Mangyongdae-guyok. The district was established by the Pyongyang City People's Committee in October 1960.
Document 14: List of tallest buildings and structures: The world's tallest artificial structure is the 829.8 - metre - tall (2,722 ft) Burj Khalifa in Dubai (of the United Arab Emirates). The building gained the official title of ``Tallest Building in the World ''and the tallest self - supported structure at its opening on January 9, 2010. The second - tallest self - supporting structure and the tallest tower is the Tokyo Skytree. The tallest guyed structure is the KVLY - TV mast.
Document 15: 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.
ground_truth: April 28
sub_queries: Ryugyong Hotel >> located in the administrative territorial entity Answer: Pyongyang
When did the torch arrive in Pyongyang ? Answer: April 28