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:       Merry Christmas , Mr . Wang . I would like to give you the book I specially chose as my appreciation for your sincere help to me in the past few days . 
 Person2:Thanks , Mr . White . That's very kind of you . 
 Person1:        I hope it will be of some use to you . 
 Person2:I am sure it will . It'll be of great help in carrying on the work I have done so far . 
 Person1:        That will be great . 

informal