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:       Mary , be calm .  
 Person2:It is impossible . You cheated on me .  
 Person1:        No , listen to me . I always regard you as my best friend . I admire you , and of course you've helped me so much . I should thank you .  
 Person2:Shut up !  
 Person1:        No , listen to me . Perhaps it's my fault that I treat everybody so well . Maybe in other people's eyes , I want you to be my girl-friend . but ... but ...  
 Person2:But you have had lily already ? You should have told me about her , but you didn't .  
 Person1:        OK ... OK ... Anyway . I will treat you as my best friend . I hope you can do the same .  
 Person2:Leave me ! Go away ! 

informal