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:       Dan , Dan , dude . You have to come over to my house right now !  
 Person2:Is everything OK ?  
 Person1:        Just get over here !  
 Person2:Come in ! Quickly !  
 Person1:        So , since when is your house a bank ?  
 Person2:What do you mean ?  
 Person1:        I mean , what ’ s up with the locks and iron bars on your windows .  
 Person2:Security , Dan , security ! You can never be too safe you know ! A lot of sickos out there . Just the other day they caught that peeping tom red handed ! Had a high power telescope and binoculars by his window .  
 Person1:        What ’ s the matter with you ? Why are you acting all paranoid ?  
 Person2:Paranoid ? I ’ m not paranoid ! I ’ m cautious ! You see Dan , we have to be on guard at all time ! People just invade your privacy as if they knew you ! Telemarketers , solicitors , even your bank ! They have way too much information ! I like to keep everything on a need to know basis .  
 Person1:        OK , well , what did you want to see me about ?  
 Person2:You are being watched ! Be careful Dan ! Be careful ! 

informal