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 courses are you taking ?  
 Person2:Chinese , maths , English , chemistry , physics , biology and so on .  
 Person1:        What do you think about the teachers ?  
 Person2:To be honest , I like most of them , except for my Chinese teacher . She is quite young , but her class is too boring !  
 Person1:        That's too bad . Do you have any foreign teachers ?  
 Person2:Yes , my oral English teacher is an American . He is from a small town in California .  
 Person1:        What is he like ?  
 Person2:He is great . He always tells us not to study for exams , and to pay more attention to communication rather than just memorizing .  
 Person1:        Are you able to follow him ?  
 Person2:Not everything , but nearly . He speaks very clearly .  
 Person1:        Oh , that's good ! He sounds like a good teacher .  
 Person2:Absolutely ! If you come to our class , I am sure you will like him . 

informal