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:       Could you help me to register for a class ?  
 Person2:Do you know what class you want to take ?  
 Person1:        Are there any Psychology classes available ?  
 Person2:I believe there are still two Psychology classes open .  
 Person1:        On what days are the classes ?  
 Person2:There is one class on Tuesday and Thursday from 2 to 4 .  
 Person1:        Can you tell me about the other class ?  
 Person2:It's from 10-12 on Monday and Wednesday .  
 Person1:        You're positive that these are the only classes left ?  
 Person2:These two are the only ones .  
 Person1:        The class on Monday and Wednesday will be fine .  
 Person2:Very good . 

formal