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:       Hi , Ben . Here are the top ten of this week's top chart .  
 Person2:Oh , great !  
 Person1:        Which is your favorite in this ten ?  
 Person2:I like No . 4 .  
 Person1:        You mean Sweet Heart .  
 Person2:Yes . In fact , I think it's much better than this week's No . 1 .  
 Person1:        What do you think about Cold Wind ?  
 Person2:I like it as well , but I don't think it's as good as Sweet Heart .  
 Person1:        So No . 4 is your favorite . Which one don't you like ?  
 Person2:Well . I don't like Your Lips very much .  
 Person1:        Why ?  
 Person2:I think it's too slow makes me sleepy . In fact , it's the worst in this week ’ s top ten , if you ask me .  
 Person1:        Really ? But it's my favorite . 

informal