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:       Hello , 8520388 2 .  
 Person2:Hi , this is Maria . Is that Shirley ?  
 Person1:        Hi , Maria , this is Shirley .  
 Person2:Shirley , do you know today's homework from our economic law class ? I have written it on a piece of paper but I can't find it now .  
 Person1:        Hold on for a moment please . I'm fetching my textbook .  
 Person2:OK .  
 Person1:        Oh , the homework is to explain what economic law is both in broad sense and in narrow sense .  
 Person2:Explain the economic law ? An essay question again ?  
 Person1:        Yes . You can use your textbook for your reference .  
 Person2:Are there any clear answers in the book to this question ?  
 Person1:        I don't think so , Maria , but I think you can look for information on the Internet .  
 Person2:OK , thank you , Shirley . You are very helpful . I have another question . When does the Economic Law of China come into effect ?  
 Person1:        Oh , there isn't such a code called economic law . The Economic Law of China is a general concept for several laws .  
 Person2:There isn't such a code ?  
 Person1:        Yes , it's a general name for several laws related to economics , like Commercial Law , and Law of Central Bank .  
 Person2:Got it . Thank you , Shirley . 

informal