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:       Thank you for your letter .  
 Person2:Is your waist any better ?  
 Person1:        Yes , I ’ m feeling very well these days .  
 Person2:I ’ m glad you are getting better .  
 Person1:        And I was glad to receive your letter .  
 Person2:Then when will you be back again ?  
 Person1:        I will be back again next Wednesday .  
 Person2:I hope to see you at that time again . Bye .  
 Person1:        Bye . 

informal