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:       How do I buy my textbooks ?  
 Person2:Do you have your book list for your class ?  
 Person1:        Yes , I have my list .  
 Person2:Fine . Once you have it , you can go to the bookstore . Do you know where that is ?  
 Person1:        Yes , I know where the bookstore is .  
 Person2:OK , so once you pass the gym , it's the first door on your left . Do you know you can also sell your used textbooks there ?  
 Person1:        No , I didn't know I could do that .  
 Person2:You just take them with you and trade them with the used textbook man just outside the door . Do you think you will be going there today ?  
 Person1:        Yes , I am going today .  
 Person2:Well , if you decide to go , I could meet you over there at 1  
 Person1:        Yes , thank you . That would be great .  
 Person2:Well , then , I'll talk to you later . Have a good day ! 

informal