In this task, you're given a passage, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.
Example: Passage: The group was occasionally diverted from strategic missions to carry out air support and interdiction missions. It supported Operation Overlord, the invasion of Normandy by attacking transportation targets, including bridges, along with airfields and strong points in France. On D Day, the squadron and the rest of the 446th Group led the first heavy bomber mission of the day. The 446th aided ground forces at Caen and Saint-Lo during July by hitting bridges, gun batteries, and enemy troops. During Operation Market Garden, the attempt to seize a bridgehead across the Rhine in the Netherlands, the 704th dropped supplies to allied troops near Nijmegen. It struck lines of communications during the Battle of the Bulge. During Operation Varsity in March 1945, it supplied ground and airborne troops near Wesel. The squadron flew its last combat mission on 25 April 1945 against Salzburg, Austria. The group had flown 273 missions and had lost 58 aircraft during the war,
. Link Information: Operation Market Garden was a failed World War II military operation fought in the Netherlands from 17 to 25 September 1944. Question: When did the operation during which the 704th dropped supplies to allied troops near Nijmegen begin?
Example solution: from 17 to 25 September 1944
Example explanation: The passage describes the 704th's actions during Operation Market Garden, and the answer specifies when the operation happened.

Problem: Passage: There is evidence that the Second Bulgarian Empire ruled at least nominally the Wallachian lands up to the RucarBran corridor as late as the late 14th century. In a charter by Radu I, the Wallachian voivode requests that tsar Ivan Alexander of Bulgaria order his customs officers at Rucar and the Dambovita River bridge to collect tax following the law. The presence of Bulgarian customs officers at the Carpathians indicates a Bulgarian suzerainty over those lands, though Radu's imperative tone hints at a strong and increasing Wallachian autonomy. Under Radu I and his successor Dan I, the realms in Transylvania and Severin continued to be disputed with Hungary. Basarab was succeeded by Nicholas Alexander, followed by Vladislav I. Vladislav attacked Transylvania after Louis I occupied lands south of the Danube, conceded to recognize him as overlord in 1368, but rebelled again in the same year; his rule also witnessed the first confrontation between Wallachia and the Ottoman Empire (a battle in which Vladislav was allied with Ivan Shishman). After the Magyar conquest (10-11th century), Transylvania had become an autonomous and multi-ethnic voivodeship led by a voivode appointed by the King of Hungary until the 16th century. Several Kings of Hungary invited settlers from Central and Western Europe, such as the Saxons, to come to Transylvania and occupy the region. The Szeklers were brought to southeastern Transylvania as border guards. Romanians are mentioned by the Hungarian documents (township called Olahteluk) in the 13th century (1283) in Bihar County. The "land of Romanians" (Terram Blacorum) appeared in Fogaras, and this area was mentioned under the name "Olachi" in 1285. After the collapse of the Hungarian Kingdom (following the disastrous Battle of Mohacs, 1526) the region became the independent Principality of Transylvania until 1711.
Link Information: The Second Bulgarian Empire (, Vtor Balgarsk Tsarstvo) was a medieval Bulgarian state that existed between 1185 and 1396. Question: Approximately how many years did the Second Bulgarian Empire rule Romania?
Solution: Answer: 211