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'.

[Q]: Person1: I am not convinced by your explanation . Could you explain it ?
Person2:Sorry , I really can't do that . There's little time left for us .
Person1: I can't accept your excuse . It's five o'clock .
Person2:Yeah . But I have an appointment with Ann .
Person1: Ok , sounds good . But I think it's your trick .
[A]: informal

[Q]: Person1: Anyone home ? Jen !
Person2:I'm in the kitchen ... let yourself in !
Person1: Wow ! You're really working up a storm !
Person2:I know . I've even worked up a sweat .
Person1: You look like a cooking show host--only messier .
[A]: formal

[Q]: Person1: Come on , fellows.Let ' s enjoy my wife's cooking !
Person2:Em , it's delicious !
Person1: Thank you ! My wife likes cooking very much .
Person2:You're lucky .
[A]:
informal