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:       I think I need some iced water , too . Is there an extra charge for that ? 
 Person2:Yes . We charge 50 cents for iced water . 
 Person1:        That's fine . Could you give me some more napkins , too ? 
 Person2:Sure . Do you need anything else ? 
 Person1:        Yes . I would also like some sweet-and-sour sauce and pepper . 
 Person2:I'll put all that into the bag for you . 
 Person1:        Do I owe you for the sauce , pepper and napkins ? 
 Person2:No , there's no charge for those . 

formal