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:       Hello Mr Janus . What can we do for you today ?  
 Person2:Hello , Miao Ping . It's that time again ; I want to convert my salary . You know , it's so annoying . I wish my company could just pay me in RIB .  
 Person1:        Haha ! I actually think that many locals would disagree with you ; they are all dying to be paid in US dollars .  
 Person2:Yes , I guess you are right . So , do you need my passport ?  
 Person1:        Thanks , Mr Janus . Of course I trust you , but regulations are regulations .  
 Person2:Here you go .  
 Person1:        Thanks . And of course , could you fill in the exchange form ? 

informal