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:       Bill , I must tell you the truth . You failed the English exam again .  
 Person2:Ah ? Really ? That stinks !  
 Person1:        Haha . April Fool's ! Did you forget what day it is today ?  
 Person2:Wow , you were pulling my leg all along . I was really fooled .  
 Person1:        Alright , now let's be serious . Actually , you get high marks in the exam . 

informal