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:       Look what you've done !  
 Person2:I'm very sorry , sir . I'll bring you a cloth immediately .  
 Person1:        Yes , and hurry up !  
 Person2:I'd like to apologize for my carelessness . May I clean it up for you ?  
 Person1:        No , I'll do it myself .  
 Person2:Here is my card , sir . Could you send me the cleaning bill and I will refund the cost to you ?  
 Person1:        I should think so , too !  
 Person2:I'm very sorry to have caused you this trouble .  
 Person1:        Yes , and please be more careful in the future !  
 Person2:I will , sir . I'm really very sorry .  
 Person1:        That's OK . 

informal