You will be given a definition of a task first, then some input of the task.
In this task you will be given a text passage from a trivia quiz. You should choose the category this question belongs to from these categories: History, Science, Social Science, Fine Arts, Literature. You can only choose one category, so if in doubt, please choose the closest match.

The beginning of this event was heralded in a speech on the twentieth anniversary of Victorious February which claimed that Klement Gottwald had failed in his handling of the trial of Rudolf Slansky. Ota Sik's "third way" was the underlying economic policy of this period, and a meeting at Cierna nad Tisou failed to put an end to it. The weakness of the Action Programme during this period led Ludvik Vaculik to publish a document which called for the resignation of inept leaders, the "Two Thousand Words". This event began after the resignation of Antonin Novotny, and in response to the end of it, Jan Palach set himself on fire in protest. Gustav Husak became President after this event was crushed by a Warsaw Pact invasion, which was justified by the Brezhnev Doctrine. This period was led by Alexander Dubcek, who attempted to create "socialism with a human face". For 10 points, name this period of liberal reforms in Czechoslovakia in 1968.
Output:
History