Input: Article: The Germans expected to negotiate an end to the war but immediately ordered an advance on Paris; by 15 September Moltke issued the orders for an investment of Paris and on 20 September the encirclement was complete. Bismarck met Favre on 18 September at the Chateau de Ferrieres and demanded a frontier immune to a French war of revenge, which included Strasbourg, Alsace and most the Moselle department in Lorraine of which Metz was the capital. In return for an armistice for the French to elect a National Assembly, Bismarck demanded the surrender of Strasbourg and the fortress city of Toul. To allow supplies into Paris, one of the perimeter forts had to be handed over. Favre was unaware that the real aim of Bismarck in making such extortionate demands was to establish a durable peace on the new western frontier of Germany, preferably by a peace with a friendly government, on terms acceptable to French public opinion. An impregnable military frontier was an inferior alternative to him, favoured only by the militant nationalists on the German side.

Now answer this question: Bismarck and Favre met on what date?

Output: 18 September

Input: Article: In July 1943, as a result of the American Federation of Musicians boycott of US recording studios, the a cappella vocal group The Song Spinners had a best-seller with "Comin' In On A Wing And A Prayer". In the 1950s several recording groups, notably The Hi-Los and the Four Freshmen, introduced complex jazz harmonies to a cappella performances. The King's Singers are credited with promoting interest in small-group a cappella performances in the 1960s. In 1983 an a cappella group known as The Flying Pickets had a Christmas 'number one' in the UK with a cover of Yazoo's (known in the US as Yaz) "Only You". A cappella music attained renewed prominence from the late 1980s onward, spurred by the success of Top 40 recordings by artists such as The Manhattan Transfer, Bobby McFerrin, Huey Lewis and the News, All-4-One, The Nylons, Backstreet Boys and Boyz II Men.[citation needed]

Now answer this question: What number one song was covered by an a cappella group in 1983?

Output: "Only You"

Input: Article: The Pyx Chamber formed the undercroft of the monks' dormitory. It dates to the late 11th century and was used as a monastic and royal treasury. The outer walls and circular piers are of 11th-century date, several of the capitals were enriched in the 12th century and the stone altar added in the 13th century. The term pyx refers to the boxwood chest in which coins were held and presented to a jury during the Trial of the Pyx, in which newly minted coins were presented to ensure they conformed to the required standards.

Now answer this question: When were newly minted coins presented to ensure they met standards?

Output:
the Trial of the Pyx