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:       Hello , Jane . What do you do in your spare time ? 
 Person2:Well , nothing special , reading , watching TV , walking , and so on . 
 Person1:        Don't you have any hobbies , like stamp collecting or things like that ? 
 Person2:No , I don't have any hobbies . How about you ? 
 Person1:        I like collecting antiques . It's expensive , but it's a lot of fun . 
 Person2:Really ? How many collections do you have ? 
 Person1:        So far I have more than 500 collections . 
 Person2:Among those collections , which is the most expensive ? 
 Person1:        A set of ancient china . It is really invaluable . 

informal