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 an attractive blouse , You look so pretty in this blue dress !  
 Person2:Really ? Thank you . I bought it in Spring Street yesterday .  
 Person1:        It's very nice.It goes well with your skirt .  
 Person2:Thank you.It ' s very nice of you to say so .  
 Person1:        Not at all.This dress certainly shows your good taste .  
 Person2:That's quite a compliment coming from you . 

informal