Given the task definition and input, reply with output. In this task, you're given passages that contain mentions of the quantity of a particular object and are supposed to find out the answer for a given question. Craft one correct answer to the question given in input. Make sure your correct answer is consistent with the context, and properly gives the exact number relating to the query.
 In your answer, use as few words as possible from the given context. To be less repetitive, please vary your language for each question.

Sentence: On January 7, 2012, Beyoncé gave birth to her first child, a daughter, Blue Ivy Carter, at Lenox Hill Hospital in New York. Five months later, she performed for four nights at Revel Atlantic City's Ovation Hall to celebrate the resort's opening, her first performances since giving birth to Blue Ivy. 
Question: How many nights did she perform at Atlantic City?

four nights