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:       Would you go to the bookstore with me ?  
 Person2:It sounds a good idea . Let ’ s go .  
 Person1:        Do you know Jeffery has published his second detective novel ?  
 Person2:Yes . I heard about that . And I know you want to buy it , but I ’ m not interested in detective novels .  
 Person1:        So what are you interested in ?  
 Person2:Magazines about fashions , such as Cosmo Polian .  
 Person1:        I know that magazine . It ’ s very popular .  
 Person2:Yes . I can lend you some .  
 Person1:        Thank you . But I ’ m not interested . 

informal