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:       Will you be joining Billy and I at the Bar ?  
 Person2:Which one will you be going to ?  
 Person1:        We are going to try the new one that opened up on 17th Street .  
 Person2:Sure , I've been meaning to visit that place myself .  
 Person1:        I want to stop off at my apartment to get changed so I should be there by 9 pm .  
 Person2:OK , can I bring a date with me ?  
 Person1:        Certainly . But if there are going to be four of us , I had better make reservations .  
 Person2:Yes . that is a very good idea . It would be a shame if we could not find a place to sit .  
 Person1:        Then I'II make reservations for 9 pm for a party of four .  
 Person2:I'll be there . Oh , is there a cover charge at the bar ?  
 Person1:        Not that I know of . Why do you ask ?  
 Person2:I want to make sure I bring enough money for my date and I .  
 Person1:        I hear the drinks and food there are moderately priced.You should be fine .  
 Person2:One last question.Is there a dress code there ?  
 Person1:        No , its very casual there . Leave your jacket and tie at home .  
 Person2:Perfect . I wanted to have a casual evening tonight .  
 Person1:        I'll see you there at 9pm .  
 Person2:Okay . See you then . 

informal