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 may I help you ?  
 Person2:I need to check these books out .  
 Person1:        Do you have your library card ?  
 Person2:Here it is .  
 Person1:        It appears that you have late fees .  
 Person2:Really ?  
 Person1:        Yes , really .  
 Person2:How much do I owe ?  
 Person1:        You owe $ 24.50 in late fees .  
 Person2:I don ’ t have that much today .  
 Person1:        I ’ m sorry , but until you pay it , you won ’ t be able to check out any more books .  
 Person2:I ’ ll pay it as soon as possible . 

informal