Celebrity Problem

There are ( N+1 ) people in a party, they might or might not know each others names.
There is one celebrity in the group (total N + 1 people), celebrity does not know any of N peoples by name and all N people know celebrity by name.

You are given the list of people’s names (N + 1),

You can ask only one question from the people.

	Do you know this name?

How many maximum number of questions you need to ask to know the celebrity name?

Note: assume all names are unique. and you know the persons by name (but don’t know if he is celebrity )