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 long can I keep these books ? 
 Person2:A month . Don't forget to return them by the due date . 
 Person1:        What if I can't finish them by then ? 
 Person2:Bring them back to the circulation desk and renew them . 
 Person1:        Any terrible fines ? 
 Person2:Sure . 

formal