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:       Hello !  
 Person2:Is that the box-office ?  
 Person1:        Yes .  
 Person2:I'd like to book two tickets for the film ' Jane Eyre ' for this evening , please .  
 Person1:        Just a minute please . Oh , I'm sorry , all the tickets for tonight have been sold out .  
 Person2:What a pity ! How about tomorrow evening ?  
 Person1:        Oh , you're lucky , there are just two tickets left . Do you want to take them ?  
 Person2:Wonderful , I'll take them .  
 Person1:        OK , your name and telephone number please .  
 Person2:Wang Min . Telephone number is 13811658 . Can I pick the tickets this afternoon ?  
 Person1:        Yes , of course .  
 Person2:Thank you very much . 

informal