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:       Good morning , Miss .  
 Person2:Morning . Can I help you ?  
 Person1:        Yes , I'd like to know how to use the library . You know , I'm a new student here .  
 Person2:All you need is your student identification card to check out books .  
 Person1:        Yes.Here ' s my identification .  
 Person2:That's all you need .  
 Person1:        Thank you very much . By the way , how many books am I allowed to check out ?  
 Person2:You can check out two books at a time . But you can't check out newspapers , magazines and periodicals ; they have to be read within library .  
 Person1:        How long can I keep the books ?  
 Person2:For two weeks . After that you must renew the books if you wish to keep them longer .  
 Person1:        I want a book on physics . Could you show me where I can find it ?  
 Person2:Yes , over there to your left . 

formal