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 are you reading ?  
 Person2:Oh , it ’ s the latest novel by ray blue . It ’ s a sic-fi thriller .  
 Person1:        I thought he usually wrote horror books .  
 Person2:He does . He ’ s good at this genre too . It ’ s a captivating read .  
 Person1:        We ’ re going to the bookshop . Would you like to join us ?  
 Person2:Yes , I would . I need to buy a textbook for my course and , as you know , I love browsing through the latest paperbacks .  
 Person1:        Me too . I need something to read on the flight to new york . I can never sleep on planes . Sarah wants to pick up some children ’ s books for her daughter .  
 Person2:I want to look at nelson Mandela ’ s autobiography .  
 Person1:        This is sure to be a worthwhile read . 

formal