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:       Did you ever take History 231 ?  
 Person2:Yeah . Last semester .  
 Person1:        Who was the professor ?  
 Person2:It was Professor Johnson .  
 Person1:        I have him this semester . What do you think about him ?  
 Person2:He's a terrible instructor and demands a lot , but fortunately , he's an easy grader .  
 Person1:        What did you end up getting ?  
 Person2:I got an A - . Sounds good , but none of my test scores were that high , so I don't know how I got a decent grade .  
 Person1:        That's probably because he grades on a curve .  
 Person2:Are you enjoying the class so far ?  
 Person1:        I hate it and I was about to withdrawal . But after hearing your experience , I think I will tough it out .  
 Person2:Yes . Definitely stay in the class . You will get a better grade than your test scores . He does that deliberately to make all the students study a lot .  
 Person1:        Thanks for letting me know . I feel relieved now . 

informal