Given a text passage, come up with an appropriate title for it. The title should accurately represent what the main focus of the passage is. The title of a passage may be present in the first few sentences of the passage and/or be referred to multiple times in the passage. The title should be 1-5 words long.

Example Input: The Horsehead Nebula ( also known as Barnard 33 ) is a dark nebula in the constellation Orion . The nebula is located just to the south of the star Alnitak , which is farthest east on Orion 's Belt , and is part of the much larger Orion Molecular Cloud Complex . The nebula was first recorded in 1888 by Scottish astronomer Williamina Fleming on photographic plate B2312 taken at the Harvard College Observatory . The Horsehead Nebula is approximately 1500 light years from Earth . It is one of the most identifiable nebulae because of the shape of its swirling cloud of dark dust and gases , which bears some resemblance to a horse 's head when viewed from Earth .
Example Output: Horsehead Nebula

Example Input: The Berlin Wall ( German : Berliner Mauer , pronounced ( blin ma ) ( listen ) ) was a guarded concrete barrier that physically and ideologically divided Berlin from 1961 to 1989 . Constructed by the German Democratic Republic ( GDR , East Germany ) , starting on 13 August 1961 , the Wall cut off ( by land ) West Berlin from virtually all of surrounding East Germany and East Berlin until government officials opened it in November 1989 . Its demolition officially began on 13 June 1990 and finished in 1992 . The barrier included guard towers placed along large concrete walls , accompanied by a wide area ( later known as the '' death strip '' ) that contained anti-vehicle trenches , '' fakir beds '' and other defenses . The Eastern Bloc portrayed the Wall as protecting its population from fascist elements conspiring to prevent the '' will of the people '' in building a socialist state in East Germany . In practice , the Wall served to prevent the massive emigration and defection that had marked East Germany and the communist Eastern Bloc during the post-World War II period .
Example Output: Berlin Wall

Example Input: During the last 10,000 years , Mount Shasta has erupted an average of every 800 years , but in the past 4,500 years the volcano has erupted an average of every 600 years . The last significant eruption on Mount Shasta may have occurred about two centuries ago .
Example Output:
Mount Shasta