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 . : For tomorrow , read pages 12 to 20 . Then do exercises one through ten on page 21 .  
 Person2:Do we have to type out our homework ?  
 Person1:        Mr . : No . You only do that when you write reports .  
 Person2:Is there anything else ?  
 Person1:        Mr . : For those of you who don't have a calculator , get one .  
 Person2:We are allowed to use a calculator in class ?  
 Person1:        Mr . : Yes . By the way , review today's notes this evening . We may have a small quiz tomorrow . 

formal