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:       Mike , did you win the lottery or something ? Why the big smile ? 
 Person2:I'm so relieved . I just passed the bar exam . 
 Person1:        You did ? That's great ! You must be very happy now ? 
 Person2:That's an understatement . I'm on cloud nine . I couldn't be any happier . 
 Person1:        Did you tell your parents yet ? 
 Person2:Not yet . I didn't get a hold of them . I'll try to call them again tonight . 
 Person1:        They're probably going to be so happy . 
 Person2:I think so . It's turning out to be a great day . 

informal