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:       Vince , I think one of your programmers is spying on us for WebTracker . 
 Person2:Pardon ? 
 Person1:        I won't say who , because I'm not sure yet . But I'll know soon . 
 Person2:Zina , I hope you're not scheming to make Elvin look bad . 
 Person1:        It isn't Elvin . 
 Person2:Dave then ? Dave is a spy for WebTracker ? You can't be serious . 
 Person1:        Loan me that tape recorder you have . And don't say anything to anyone until I come back . 

informal