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:       Julia , why have you prepared a candlelight dinner ? Anything special to celebrate ? Did you get a promotion ?  
 Person2:Honey , don't tell me that you forgot our anniversary , did you ?  
 Person1:        Oh , my dear , how can I forget such an important day ? I was just kidding . Look at this box .  
 Person2:What's in it ?  
 Person1:        Have a guess .  
 Person2:A necklace ?  
 Person1:        No .  
 Person2:I have no idea .  
 Person1:        Open it now .  
 Person2:Oh , my god . A diamond brooch . It's so beautiful . You're so kind to me , A . Thank you !  
 Person1:        You're welcome , honey . I hope we will celebrate our golden wedding anniversary in future . 

informal