Question: When did the torch arrive in the city that contained Sosong-guyok?

full_context: Document 1: 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 2: 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 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: Ryokpo-guyok: Ryŏkp'o-guyŏk, or Ryŏkp'o District is one of the 19 guyŏk that constitute Pyongyang, North Korea. This is where part of the Complex of Goguryeo Tombs of Pyongyang can be found.
Document 5: 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 6: Suseo-dong: Suseo-dong is a ward of Gangnam-gu in Seoul, South Korea. The name, "Suseo" originated from the feature of Han River running through the western part of the region. Suseo-dong is also home to the Tancheon park.
Document 7: 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 8: 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 9: Sadong-guyok: Sadong-guyŏk, or Sadong District, is one of the 19 guyŏk, and one of the six, that constitute East Pyongyang, North Korea. It is on the eastern bank of the Taedong River, and the mouth of the Nam River. It is north of Ryŏkp'o-guyŏk (Ryokpho District), east of Taedonggang-guyŏk (Taedonggang District) and north east of Tongdaewŏn-guyŏk. It was established in September 1959.
Document 10: 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 11: Tongdaewon-guyok: Tongdaewŏn-guyŏk or Tongdaewon District is one of the 20 wards, and one of the six that constitute East Pyongyang, North Korea. It sits on the eastern bank of the Taedong River. It is north of Sŏn'gyo-guyŏk (Songyo District), south of Taedonggang-guyŏk (Taedonggang District) and west of Sadong-guyŏk (Sadong District) and Ryŏkp'o-guyŏk (Ryokpho District). It was established in October 1960.
Document 12: Songyo-guyok: Sŏn'gyo-guyŏk or Songyo District is one of the 19 guyŏk that constitute the city of Pyongyang, North Korea. It is on the eastern bank of the Taedong River at the center of East Pyongyang. It is bordered to the south by Nakrang-guyok, to the north by Tongdaewon-guyok and to the east by Ryokpo and Sadong-guyoks. It was established in September 1959.
Document 13: Sosong-guyok: Sŏsŏng-guyŏk, or Sosong District, is one of the 19 guyŏk of Pyongyang, North Korea. It is located on the Pot'ong River, west of the Moranbong-guyŏk (Moranbong District) and south of Hyŏngjesan-guyŏk (Hyongjesan District). It was established January 1958.
Document 14: 2008 Summer Olympics torch relay: Chinese officials canceled the torch relay ceremony amidst disruptions, including a Tibetan flag flown from a window in the City Hall by Green Party officials. The third torchbearer in the Paris leg, Jin Jing, who was disabled and carried the torch on a wheelchair, was assaulted several times by unidentified protestors seemingly from the pro-Tibet independent camp. In interviews, Jin Jing said that she was "tugged at, scratched" and "kicked", but that she "did not feel the pain at the time." She received praise from ethnic Chinese worldwide as "Angel in Wheelchair". The Chinese government gave the comment that "the Chinese respect France a lot" but "Paris [has slapped] its own face."
Document 15: 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.
ground_truth: April 28
sub_queries: Sosong-guyok >> located in the administrative territorial entity Answer: Pyongyang
When did the torch arrive in Pyongyang ? Answer: April 28