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:       I'm terrible sorry . I seem to have mislaid your MP4 .  
 Person2:Don't worry about that .  
 Person1:        Very sorry that I have caused you so much trouble .  
 Person2:No trouble at all .  
 Person1:        Won't you let me buy a new one tomorrow ?  
 Person2:No , that's quite out of the question .  
 Person1:        Please accept my deep apology .  
 Person2:I never did like this MP4 anyway . I won't hear of it . 

informal