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:       we are going out for dinner tonight . Are you coming , Betty ? 
 Person2:I'm not sure . I have to check my schedule . Where are you going ? 
 Person1:        oh , Jake made a reservation at Friday's . 
 Person2:Jack ? 
 Person1:        yes , the one with the R $ D team . Is that a problem ? 
 Person2:I will never go out with him anymore . 
 Person1:        why did you say so ? 
 Person2:last time when we had dinner at the Smith's , it was a horrible experience . He had no manners at all ! 
 Person1:        oh , really ? 
 Person2:he made a lot of noises while eating . He talked with his mouth full and sipped loudly . 
 Person1:        are you kidding me ? How could he behave like that ? 
 Person2:it is true . Everyone kept looking at him . It was so embarrassing as I was sitting right next to him . 
 Person1:        what a shame ! Didn't he realized that ? 
 Person2:I have no idea . He seemed to enjoy the dinner very much . 
 Person1:        maybe he should really something about eating etiquette . 
 Person2:oh , he really should . 

informal