Input: Read this: The Republic of the Congo (French: République du Congo), also known as Congo, Congo Republic, West Congo[citation needed], or Congo-Brazzaville, is a country located in Central Africa. It is bordered by five countries: Gabon to the west; Cameroon to the northwest; the Central African Republic to the northeast; the Democratic Republic of the Congo to the east and south; and the Angolan exclave of Cabinda to the southwest.
Question: What is the Central African Republic also known as?

Output: unanswerable


Input: Read this: From April–July, Soviet and German officials made statements regarding the potential for the beginning of political negotiations, while no actual negotiations took place during that time period. The ensuing discussion of a potential political deal between Germany and the Soviet Union had to be channeled into the framework of economic negotiations between the two countries, because close military and diplomatic connections, as was the case before the mid-1930s, had afterward been largely severed. In May, Stalin replaced his Foreign Minister Maxim Litvinov, who was regarded as pro-western and who was also Jewish, with Vyacheslav Molotov, allowing the Soviet Union more latitude in discussions with more parties, not only with Britain and France.
Question: Which three countries positioned themselves to broker a deal returning to a pre-1930’s treaty with each other?

Output: unanswerable


Input: Read this: Infrared reflectography (fr; it; es), as called by art conservators, can be applied to paintings to reveal underlying layers in a completely non-destructive manner, in particular the underdrawing or outline drawn by the artist as a guide. This often reveals the artist's use of carbon black, which shows up well in reflectograms, as long as it has not also been used in the ground underlying the whole painting. Art conservators are looking to see whether the visible layers of paint differ from the underdrawing or layers in between – such alterations are called pentimenti when made by the original artist. This is very useful information in deciding whether a painting is the prime version by the original artist or a copy, and whether it has been altered by over-enthusiastic restoration work. In general, the more pentimenti the more likely a painting is to be the prime version. It also gives useful insights into working practices.
Question: What is visible in alterations of paintings?

Output: unanswerable


Input: Read this: Thermal mass systems can store solar energy in the form of heat at domestically useful temperatures for daily or interseasonal durations. Thermal storage systems generally use readily available materials with high specific heat capacities such as water, earth and stone. Well-designed systems can lower peak demand, shift time-of-use to off-peak hours and reduce overall heating and cooling requirements.
Question: What is something that can be accomplished by a thermal mass system?

Output:
reduce overall heating and cooling requirements