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:       May I help you with something ? 
 Person2:I would like to return these books . 
 Person1:        What happened to this book ? 
 Person2:I dropped it , and the cover tore off . 
 Person1:        I ’ m going to have to charge you for the damage . 
 Person2:How much ? 
 Person1:        It ’ s only $ 5 . 
 Person2:That ’ s not too bad . 
 Person1:        I know it ’ s not . 
 Person2:Here ’ s the money for the book . 
 Person1:        Thank you for your payment . 
 Person2:You are very welcome . 

formal