Definition: You are given a conversation between two people. 'Person1:' and 'Person2:' are used to separate their respective dialogues. You are required to assign a label 'formal' if there is an absence of emotion and a presence of questions anywhere within the conversation. If such pattern is not found assign the label 'informal'.
Input:  Person1:       Good morning . I'd like to check out right now . 
 Person2:May I have your room number 。 Sir ? 
 Person1:        Room 103 . 
 Person2:Just a minute , Sir.Are you Mr Wang from China ? 
 Person1:        Yes.Wang Bin . 
 Person2:Mr Wang , did you sign any bill in the last two hours in our hotel ? 
 Person1:        No . 
 Person2:Have you used any hotel services this morning ? 
 Person1:        No , I have not . 
 Person2:Here is your bill.It totals 3250 dollars . 
 Person1:        All right . Can I pay with credit cards ? 
 Person2:What kind of card ? 
 Person1:        American Express . 
 Person2:Yes , we do . Here is your bill and receipt . 

formal