Question: What is the largest football in the world called in the country that neighbors the country Deoksancheon is located?

full_context: Document 1: Kim Il-sung Stadium: Kim Il-sung Stadium is the name of a large multi-purpose stadium located in Pyongyang, the capital city of the Democratic People's Republic of Korea.
Document 2: Anyangcheon: The Anyangcheon is a river in Gyeonggi-do and Seoul, South Korea. It has its source on the slopes of Mount Gwanggyo in the city of Uiwang and flows north, through the city of Gunpo, where a major cleanup operation saw several species of birds return to the area in 2005. Here, though, the water table remains depleted. The river then flows through Anyang City, where it is met by its major tributary, the Hakuicheon stream. From here, it loops around to the west before continuing north to the border with Gwangmyeong City. As the river passes to the west of Mount Gwanak, it forms the border between Gwangmyeong and Seoul, where it is lined on the Gwangmyeong side with rape fields and cherry blossom trees. After the stream is joined near Guil Station from the west by the Mokgamcheon stream, which forms another border between Gwangmyeong and Seoul, it is then totally within the capital. Here, it is also joined from the east by the Dorimcheon and passes through a conservation zone for migratory birds which was established after a 2005 cleanup operation, whereafter it joins the Han. Most of the length of the river has a path alongside providing easy access, the only parts without this lying in Uiwang. Seoul City Council has embarked on a programme of exclusive cycle path creation alongside its waterways, including the Anyangcheon, to be completed in 2010.
Document 3: 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 4: Deoksancheon: Deoksancheon is a river of South Korea. It is a tributary of the Hongcheon River in the Han River system. The river is located in a high altitude area. There are alluvium deposits along the lower end of the stream.
Document 5: Sunan Stadium: Sunan Stadium is a multi-purpose stadium in Pyongyang, North Korea. It is currently used mostly for football matches. The stadium holds 40,000 spectators and opened in 1991.
Document 6: Geography of Japan: Japan is an island nation in East Asia comprising a volcanic archipelago extending along the continent's Pacific coast. It lies between 24 ° to 46 ° north latitude and from 123 ° to 146 ° east longitude. Japan is southeast of the Russian Far East, separated by the Sea of Okhotsk; slightly east of the Korean Peninsula, separated by the Sea of Japan; and east - northeast of China and Taiwan, separated by the East China Sea. The closest neighboring country to Japan is Russia.
Document 7: Duiwenhoks River: Duiwenhoks River, located in Western Cape, South Africa, drains the Langeberg Mountains and flows south to the coast, entering the sea west of Mossel Bay in the Southern Cape. The river is approximately 83 km long with a catchment area of 1 340 km. The Noukrans River is a tributary.
Document 8: Dorimcheon: The Dorimcheon is a river in Seoul, South Korea. It has its source in the valley between Gwanaksan and Samseongsan in southern Seoul and flows north, past Seoul National University. From Sillim Station to Daerim Station, it is covered by Line 2 of the Seoul Subway, which is elevated above the stream for this distance, so it is still possible to walk alongside the waterway. The river empties into the Anyangcheon 250m beyond the western the end of Dorimcheon Station's platforms.
Document 9: Geography of South Korea: South Korea is located in East Asia, on the southern half of the Korean Peninsula jutting out from the far east of the Asian land mass. The only country with a land border to South Korea is North Korea, lying to the north with 238 kilometres (148 mi) of border running along the Korean Demilitarized Zone. South Korea is mostly surrounded by water and has 2,413 kilometres (1,499 mi) of coast line along three seas; to the west is the Yellow Sea (known in Korea as West Sea), to the south is the East China Sea, and to the east is the Sea of Japan (known in Korea as East Sea). Geographically, South Korea's land mass is approximately 100,032 square kilometres (38,623 sq mi). 290 square kilometres (110 sq mi) of South Korea are occupied by water. The approximate coordinates are 37 ° North, 127 ° 30 East. Notable islands include Jeju Island (Jejudo), Ulleung Island (Ulleungdo), and Liancourt Rocks (Dokdo, known in Japan as Takeshima).
Document 10: Rungrado 1st of May Stadium: The Rungrado 1st of May Stadium, also known as the May Day Stadium, is a multi-purpose stadium in Pyongyang, North Korea, completed on 1 May 1989. It is the largest stadium in the world, with a total capacity of 114,000. The site occupies an area of 20.7 hectares (51 acres).
Document 11: Pyongyang Gymnasium: Pyongyang Gymnasium, also known as Pyongyang Indoor Stadium, is an indoor sporting arena located in Pyongyang, North Korea. The capacity of the arena is for 20,100 people and was opened in 1973. It is used to host indoor sporting events, such as basketball and volleyball, as well as concerts.
Document 12: Geography of Vietnam: Vietnam is located on the eastern margin of the Indochinese peninsula and occupies about 331,211.6 square kilometers, of which about 25% was under cultivation in 1987. It borders the Gulf of Thailand, Gulf of Tonkin, and Pacific Sea, alongside China, Laos, and Cambodia. The S - shaped country has a north - to - south distance of 1,650 kilometers and is about 50 kilometers wide at the narrowest point. With a coastline of 3,260 kilometers, excluding islands, Vietnam claims 12 nautical miles (22.2 km; 13.8 mi) as the limit of its territorial waters, an additional 12 nautical miles (22.2 km; 13.8 mi) as a contiguous customs and security zone, and 200 nautical miles (370.4 km; 230.2 mi) as an exclusive economic zone.
Document 13: 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 14: South Korea: The country, including all its islands, lies between latitudes 33 ° and 39 ° N, and longitudes 124 ° and 130 ° E. Its total area is 100,032 square kilometres (38,622.57 sq mi).
Document 15: South Korea: South Korea occupies the southern portion of the Korean Peninsula, which extends some 1,100 km (680 mi) from the Asian mainland. This mountainous peninsula is flanked by the Yellow Sea to the west, and the Sea of Japan to the east. Its southern tip lies on the Korea Strait and the East China Sea.
ground_truth: The Rungrado 1st of May Stadium, also known as the May Day Stadium
sub_queries: Deoksancheon >> country Answer: South Korea
what are the neighboring countries of South Korea Answer: North Korea
largest football stadium in the world North Korea Answer: The Rungrado 1st of May Stadium, also known as the May Day Stadium