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: Just make yourself at home .
Person2:Thank you . You are cooking up a storm .
Person1: Wouldn't you like some more chicken ?
Person2:No , thank you . I'm afraid I can't take in anymore .

Output: informal

Input: Consider Input: Person1: I need to eat something .
Person2:You just ate .
Person1: I know , but I'm hungry again .
Person2:There's no food left from dinner .
Person1: I think I'm going to go make myself a snack .
Person2:Do you know what kind of snack that you want ?
Person1: I'm not exactly sure .
Person2:Why don't you make yourself a sandwich or something ?
Person1: I have no idea what kind of sandwich I want to make .
Person2:A PB & J is pretty easy to make .
Person1: I'm going to do that .
Person2:Knock yourself out .
Output: formal