This task is about creating an unanswerable question based on a given passage. Construct a question that looks relevant to the given context but is unanswerable. Following are a few suggestions about how to create unanswerable questions:
(i) create questions which require satisfying a constraint that is not mentioned in the passage
(ii) create questions which require information beyond what is provided in the passage in order to answer
(iii) replace an existing entity, number, date mentioned in the passage with other entity, number, date and use it in the question
(iv) create a question which is answerable from the passage and then replace one or two words by their antonyms or insert/remove negation words to make it unanswerable.

Input: Consider Input: Passage: Even though some proofs of complexity-theoretic theorems regularly assume some concrete choice of input encoding, one tries to keep the discussion abstract enough to be independent of the choice of encoding. This can be achieved by ensuring that different representations can be transformed into each other efficiently.

Output: What can not be achieved by ensuring different representations can transformed into each other efficiently?


Input: Consider Input: Passage: Other widely used alloys that contain zinc include nickel silver, typewriter metal, soft and aluminium solder, and commercial bronze. Zinc is also used in contemporary pipe organs as a substitute for the traditional lead/tin alloy in pipes. Alloys of 85–88% zinc, 4–10% copper, and 2–8% aluminium find limited use in certain types of machine bearings. Zinc is the primary metal used in making American one cent coins since 1982. The zinc core is coated with a thin layer of copper to give the impression of a copper coin. In 1994, 33,200 tonnes (36,600 short tons) of zinc were used to produce 13.6 billion pennies in the United States.

Output: What has zinc been replaced with in pipe organs?


Input: Consider Input: Passage: United States v. LaMacchia 871 F.Supp. 535 (1994) was a case decided by the United States District Court for the District of Massachusetts which ruled that, under the copyright and cybercrime laws effective at the time, committing copyright infringement for non-commercial motives could not be prosecuted under criminal copyright law. The ruling gave rise to what became known as the "LaMacchia Loophole," wherein criminal charges of fraud or copyright infringement would be dismissed under current legal standards, so long as there was no profit motive involved.


Output: When was United States v. LaMacchia not contested?