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: Consider Input: Person1: Will you bring our bill , please ?
Person2:Yes , certainly . I'll be back in a minute . Here you are
Person1: Thanks.Let me see . I think there's a mistake on the bill here.Would you mind checking , please ?
Person2:Of course , not.Let me check.Oh , you seem bo be correct .
Person1: How about tax and service charge ?
Person2:Only ten percent tax is included in the bill .
Person1: Then one hundred U . S . dollars covers everything , doesn't it ?
Person2:It sure does .

Output: informal

Input: Consider 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 .

Output: informal

Input: Consider Input: Person1: I'm sorry , but I can't come to your party .
Person2:What a shame !
Output: informal