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:       Mr . Smith is really a thorough drag . 
 Person2:What is it ? 
 Person1:        He's endless talking about stocks almost bores me to death . 
 Person2:Don't you like to know anything about stocks ? 
 Person1:        I'm not at all keen on this subject . 

informal