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:       How much are these apples ? 
 Person2:Let me weigh them for you . 1.5 $ . 
 Person1:        Do you accept coupons ? 
 Person2:Yes . 
 Person1:        Here are my coupons . Is that enough ? 
 Person2:You have to pay $ 0.5 more . 

formal