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:       Excuse me , Professor . I think there might be an error in my test score . 
 Person2:Sure . Do you think that the total is wrong or that you got something marked wrong that should have been marked right ? 
 Person1:        I think that the percentage is incorrect . 
 Person2:Let's just go over all of it to double-check . 
 Person1:        Sure , let's do it . 
 Person2:Here is the answer sheet . Do you see a place where I marked something wrong that should have been right ? 
 Person1:        I don't see any mistakes . 
 Person2:OK , now that we've gotten those straightened out , let's total the score . 
 Person1:        Yes , let's total it . 
 Person2:Well , if I total that like this and divide by this number , I get this total . Do you agree ? 
 Person1:        Yes , you're right . 
 Person2:Well then , we are all straight . Have a good day and thanks for bringing that to my attention . 

informal