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 , Bill !  
 Person2:Merry Christmas . Steven !  
 Person1:        What do you want to do to celebrate Christmas ?  
 Person2:I'll have supper with my girlfriend and go shopping . What about you ?  
 Person1:        I'll go to church first and then go to a Christmas party . Would you like to come ?  
 Person2:I'd love to . But I am going to meet my girlfriend right now . See you later .  
 Person1:        See you . 

informal