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:       Mm ... How do I get this ticket machine to work ?  
 Person2:Well first put your money in .  
 Person1:        Ok , I ’ Ve done that .  
 Person2:Then just press this button .  
 Person1:        Oh it ’ s printed the ticket already . Thank you very much .  
 Person2:You ’ re welcome . 

informal