Definition: In this task, you need to generate an appropriate title for the given summary of some paragraph. The generated title must be short and should include the main topic of the given text. Your summary should be less than 20 words long.
Input: The bells on Londonderry's two cathedrals are to ring out in harmony as part of a UK-wide celebration of the London 2012 Olympics.

Derry's two cathedrals join UK-wide Olympic bell ring