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:       I've been thinking of taking I've been thinking of taking a Crazy English course.Do you think it's a good idea  
 Person2:Sure ! You should do anything you can to improve your English .  
 Person1:        Really ? Do you think English is that important ?  
 Person2:Of course it is.In fact , I'll even take the course with you if you want .  
 Person1:        Great ! It's always better to do things with a friend .  
 Person2:Do you have the phone number ? I need to call for registration .  
 Person1:        No , I left it at home.Sorry !  
 Person2:That's OK . I can get it from you later .  
 Person1:        So , do you want to go somewhere for dinner and practice our English together tonight ?  
 Person2:All right . I know a great restaurant near here.But , it's a little expensive and I don't have much money with me .  
 Person1:        No problem . I just got paid.It ' s my treat .  
 Person2:Thank you ! I'll be sure to return the favor after our first class , OK ?  
 Person1:        Forget it ! That's what friends are for ! Besides , I have a VIP card for a discount .  
 Person2:Good job ! This is going to be a great night !  
 Person1:        I think so too.Let ' s go ! 

informal