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:       Would you please bring us the check ? 
 Person2:Sure , here you are . It comes to $ 84 . 
 Person1:        Does that include the service charge ? 
 Person2:No . sir , we charge separately . 
 Person1:        Here you are . Keep the change . 

informal