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:       What is the matter with you ? 
 Person2:I've got a sore throat and my chest hurts . 
 Person1:        How long have you been like this ? 
 Person2:It has been two or three days . 
 Person1:        I think you've got a flu.Take this prescription to the chemist's and then go back and sleep . 
 Person2:Thank you very much . 
 Person1:        Don't worry about your flu . You will be OK soon . 
 Person2:Thank you . 

formal