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:       The central Hotel , please . I have to be there by 6:00 .  
 Person2:We shouldn't have any trouble if the traffic isn't too heavy . Is this your first trip here ?  
 Person1:        Yes . I've never been here before .  
 Person2:You haven't seen the sights yet , have you ?  
 Person1:        No , I'm open to suggestions .  
 Person2:Why don't you visit the Great Wall first ?  
 Person1:        That's a good idea .  
 Person2:Here we are . That will be seven yuan and seventy cents .  
 Person1:        Thanks a lot . Here's ten yuan . Keep the change . 

informal