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:       Okay , I want to change 22,000 .  
 Person2:Could you please fill out this form ?  
 Person1:        Okay , here you are . ( She hands the completed form and the money to the clerk . )  
 Person2:Here's your $ 200 .  
 Person1:        Thank you very much .  
 Person2:Thank you . 

informal