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 like anything else , sir ?  
 Person2:May I have some water , please ?  
 Person1:        Certainly . Would you like your coffee with your dinner or later ?  
 Person2:With my dinner , please . And can you take my order for dessert later ?  
 Person1:        Of course . 

informal