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: Iraqi Prime Minister Haider al-Abadi says the destruction of an ancient mosque in the city of Mosul is "an official declaration of defeat" by so-called Islamic State (IS).

Battle for Mosul: Destruction of al-Nuri mosque 'shows IS defeated'