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:       How may I help you ?  
 Person2:I want to return this video .  
 Person1:        Is that all you need ?  
 Person2:I also need to check these books out .  
 Person1:        Anything else ?  
 Person2:That ’ s everything .  
 Person1:        I need your library card .  
 Person2:I have it . Here you go .  
 Person1:        Do you need anything else ?  
 Person2:That ’ s everything .  
 Person1:        Your books are due back two weeks from today .  
 Person2:Thank you . Good night . 

formal