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:       Can I help you ?  
 Person2:Have you got the latest ONXIU magazine ?  
 Person1:        Yes , but it's checked out .  
 Person2:What a pity ! I missed it again .  
 Person1:        It's popular you know . You want to reserve it ?  
 Person2:Yes , please .  
 Person1:        Fill out this form and we will send you a note when we get the book .  
 Person2:Thank you . What shall I do when I check out these books ?  
 Person1:        Take the card , and fill in your name and library card number .  
 Person2:Thank you so much . 

informal