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's your favorite book ?  
 Person2:It's Gone With the Wind .  
 Person1:        Why do you like it best ?  
 Person2:I enjoy the various characters and the plot .  
 Person1:        Well . I like the Thorn Birds best .  
 Person2:Is it very interesting ?  
 Person1:        Sure . I like the writer's language , too .  
 Person2:If I have a chance , I'll enjoy the book .  
 Person1:        Would you like to go to the bookshop with me ?  
 Person2:That's a good idea . Let's go ! 

informal