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:       Good morning , Madam , can I take your order now ?  
 Person2:Yes , I'd like to have a roast chicken leg .  
 Person1:        Anything else ?  
 Person2:No .  
 Person1:        How about drink ?  
 Person2:No , enough .  
 Person1:        Please wait a moment .  
 Person2:Waiter , come back .  
 Person1:        OK . What's up , Madam ?  
 Person2:It's not too salty .  
 Person1:        OK .  
 Person2:Waiter , come back again .  
 Person1:        Yes , anything wrong ?  
 Person2:Not too rare .  
 Person1:        Yes , I see .  
 Person2:Why do you come back again ?  
 Person1:        There's a question I want to ask you .  
 Person2:What's that ?  
 Person1:        Which leg do you want to have , right leg or left one ?  
 Person2:Thanks , thanks a lot and thanks a million .  
 Person1:        Why do you say so many thanks ?  
 Person2:I can't forget about this when next time . 

informal