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:       Can I help you , sir ?  
 Person2:You have so many antiques and Chinese paintings here . May I have a look first ?  
 Person1:        Of course .  
 Person2:Are they genuine ?  
 Person1:        Some are genuine . But all our reproductions are clearly marked and priced . 

informal