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:       Hey , Dora ! What kind of books do you like to read ?  
 Person2:I read everything I can get my hands on but I like love stories best . What do you think about the love stories ?  
 Person1:        I hate to tell you this , but they are nothing but sob stories .  
 Person2:I don't think so . I like them . Then what's your favorite book ?  
 Person1:        I'm fond of history books .  
 Person2:Oh , the history books are dull to me . 

formal