You will be given a definition of a task first, then some input of the task.
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'.

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 .
Output:
informal