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:       Hi , Walter ! 
 Person2:Hi , Sterling ! 
 Person1:        What do you think of our new teacher ? 
 Person2:Professor Wood ? I think he's a brilliant scientist . 
 Person1:        You're got a point there.But do you think he's a little absent-minded ? 
 Person2:I guess so . 

formal