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 can I do for you ? 
 Person2:I ’ m returning these books . 
 Person1:        Let me have them . 
 Person2:Here are all of them . 
 Person1:        These books are two weeks late . 
 Person2:I didn ’ t have time to return them . 
 Person1:        You ’ re going to have to pay late fees . 
 Person2:How much ? 
 Person1:        25 cents a day . 
 Person2:25 cents a day ? 
 Person1:        That means 25 cents for each late book . 
 Person2:That ’ s expensive . 

informal