Question: When did the country with Horyonggoksa split from the country that manufactures Koksan?

full_context: Document 1: AEK-971: The AEK-971 is a Russian (formerly the Soviet Union) selective fire 5.45×39mm assault rifle that was developed at the Kovrov Mechanical Plant (KMZ) by chief designer Sergey Koksharov in the late 1970s and 1980s (currently manufactured by Degtyarev Plant).
Document 2: Nuclear weapon design: In 1999, nuclear weapon design was in the news again, for the first time in decades. In January, the U.S. House of Representatives released the Cox Report (Christopher Cox R-CA) which alleged that China had somehow acquired classified information about the U.S. W88 warhead. Nine months later, Wen Ho Lee, a Taiwanese immigrant working at Los Alamos, was publicly accused of spying, arrested, and served nine months in pre-trial detention, before the case against him was dismissed. It is not clear that there was, in fact, any espionage.
Document 3: Division of Korea: The subsequent Korean War, which lasted from 1950 to 1953, ended with a stalemate and has left the two Koreas separated by the Korean Demilitarized Zone (DMZ) up to the present day.
Document 4: Korean War: By mid-1950, North Korean forces numbered between 150,000 and 200,000 troops, organized into 10 infantry divisions, one tank division, and one air force division, with 210 fighter planes and 280 tanks, who captured scheduled objectives and territory, among them Kaesong, Chuncheon, Uijeongbu, and Ongjin. Their forces included 274 T-34-85 tanks, 200 artillery pieces, 110 attack bombers, some 150 Yak fighter planes, 78 Yak trainers, and 35 reconnaissance aircraft. In addition to the invasion force, the North KPA had 114 fighters, 78 bombers, 105 T-34-85 tanks, and some 30,000 soldiers stationed in reserve in North Korea. Although each navy consisted of only several small warships, the North and South Korean navies fought in the war as sea-borne artillery for their in-country armies.
Document 5: History of Korea: After the end of WWII in 1945, the Allies divided the country into a northern area, protected by the Soviets, and a southern area protected primarily by the United States. In 1948, when the powers failed to agree on the formation of a single government, this partition became the modern states of North and South Korea. The peninsula was divided at the 38th Parallel: the ``Republic of Korea ''was created in the south, with the backing of the US and Western Europe, and the`` Democratic People's Republic of Korea'' in the north, with the backing of the Soviets and the communist People's Republic of China. The new premier of North Korea, Kim il - Sung launched the Korean War in 1950 in an attempt to reunify the country under Communist rule. After immense material and human destruction, the conflict ended with a cease - fire in 1953. The two nations officially remain at war because a peace treaty was never signed. Both states were accepted into the United Nations in 1991.
Document 6: Military Demarcation Line: The Military Demarcation Line (MDL), sometimes referred to as the Armistice Line, is the 154 mile - long land border or demarcation line between North Korea and South Korea. On either side of the line is the Korean Demilitarized Zone (DMZ). The MDL and DMZ were established by the Armistice at the end of the Korean War in 1953.
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: Koksan (artillery): The M-1978 Koksan is a 170 mm self-propelled gun of North Korean design and manufacture. Very little information is available due to the secretive nature of the North Korean government. The designations "M-1978" and "Koksan" were given to the type by American military analysts, as they first became aware of it in that year in Koksan, North Korea.
Document 9: Korean War: The Demilitarized Zone runs northeast of the 38th parallel; to the south, it travels west. The old Korean capital city of Kaesong, site of the armistice negotiations, originally was in pre-war South Korea, but now is part of North Korea. The United Nations Command, supported by the United States, the North Korean People's Army, and the Chinese People's Volunteers, signed the Armistice Agreement on 27 July 1953 to end the fighting. The Armistice also called upon the governments of South Korea, North Korea, China and the United States to participate in continued peace talks. The war is considered to have ended at this point, even though there was no peace treaty. North Korea nevertheless claims that it won the Korean War.
Document 10: Division of Korea: The division of Korea between North and South Korea occurred after World War II, ending the Empire of Japan's 35 - year rule over Korea in 1945. The United States and the Soviet Union each occupied a portion of the peninsula, with the boundary between their zones of control along the 38th parallel.
Document 11: 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 12: KM-SAM: The KM-SAM is the middle-tier of South Korea's three-tier aerial and missile defense system. Though it was developed in Russia by the Almaz Design Bureau with assistance from Samsung Thales, LIG Nex1, and Doosan DST, localization and industrialization were done in South Korea enough to consider it an indigenous system. The Cheongung (Iron Hawk) can intercept targets up to an altitude of at a range of . It is to replace upgraded MIM-23 Hawk batteries in South Korea and be made available for export. Almaz-Antey continued with the program after prototypes were transferred and have created a distinctly Russian version called the Vityaz missile system.
Document 13: Namsan (Gyeongju): Namsan (남산, "South Mountain") is a 494-meter peak in the heart of Gyeongju National Park, just south of Gyeongju, South Korea. The mountain is within easy reach from the city and attracts a large number of national tourists. Namsan covers an area of about 8 km (north-south) by 12 km (east-west). Some 180 peaks are counted, of which Geumobong (468 m) and Gouibong (495 m) are the best-known. There are about 40 valleys.
Document 14: 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 15: Horyonggoksan: Horyonggoksan is a mountain in Incheon, South Korea. The mountain is on the southern end of Muuido, in the district of Jung-gu. It has an elevation of .
ground_truth: 1953
sub_queries: Koksan >> manufacturer Answer: North Korea
Horyonggoksan >> country Answer: South Korea
when did North Korea split from #2 Answer: 1953