Input: Read this: In the United States, as part of the FCC's plug and play agreement, cable companies are required to provide customers who rent HD set-top boxes with a set-top box with "functional" FireWire (IEEE 1394) on request. None of the direct broadcast satellite providers have offered this feature on any of their supported boxes, but some cable TV companies have. As of July 2004[update], boxes are not included in the FCC mandate. This content is protected by encryption known as 5C. This encryption can prevent duplication of content or simply limit the number of copies permitted, thus effectively denying most if not all fair use of the content.
Question:  What can 5c encryption not prevent?

Output: unanswerable


Input: Read this: By the 9th century, Catalan had evolved from Vulgar Latin on both sides of the eastern end of the Pyrenees, as well as the territories of the Roman province of Hispania Tarraconensis to the south. From the 8th century onwards the Catalan counts extended their territory southwards and westwards at the expense of the Muslims, bringing their language with them. This process was given definitive impetus with the separation of the County of Barcelona from the Carolingian Empire in 988.
Question: When did the County of Barcelona separate from the Carolengian Empire?

Output: 988


Input: Read this: The bells at the abbey were overhauled in 1971. The ring is now made up of ten bells, hung for change ringing, cast in 1971, by the Whitechapel Bell Foundry, tuned to the notes: F#, E, D, C#, B, A, G, F#, E and D. The Tenor bell in D (588.5 Hz) has a weight of 30 cwt, 1 qtr, 15 lb (3403 lb or 1544 kg).
Question: When weren't the bells overhauled?

Output: unanswerable


Input: Read this: Antigonus then sent his son Demetrius to regain control of Greece. In 307 he took Athens, expelling Demetrius of Phaleron, Cassander's governor, and proclaiming the city free again. Demetrius now turned his attention to Ptolemy, defeating his fleet at the Battle of Salamis and taking control of Cyprus. In the aftermath of this victory, Antigonus took the title of king (basileus) and bestowed it on his son Demetrius Poliorcetes, the rest of the Diadochi soon followed suit. Demetrius continued his campaigns by laying siege to Rhodes and conquering most of Greece in 302, creating a league against Cassander's Macedon.
Question: When did Demetrius take control of Athens?

Output:
307