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:       What can I do for you ? 
 Person2:I am returning these books . 
 Person1:        What did you do to this book ? 
 Person2:I accidentally ripped the cover . 
 Person1:        You will need to pay for the damage . 
 Person2:How much do I need to pay ? 
 Person1:        I ’ m going to need $ 5.00 . 
 Person2:That ’ s not too expensive . 
 Person1:        It isn ’ t . 
 Person2:Here ’ s the $ 5.00 . 
 Person1:        Thank you . 
 Person2:No problem . Have a good one . 

formal