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: Excuse me , is this seat taken ?
Person2:Er ... no , go ahead .
Person1: You work upstair , right ? I think I have seen you before . I'm Karren , Karren Brown .
Person2:Nice to meet you , Karren . I'm Tim Wang .
Person1: Happy to know you , Tim .
[A]: informal

[Q]: Person1: Good morning , Mary !
Person2:Good morning , John !
Person1: I want to have a few friends over for a dinner party to celebrate my birthday . Would you be able to come the next weekend on Saturday ?
Person2:I'd be delighted to , John . Saturday did you say ?
Person1: Yes , if that's all right for you .
Person2:I'm pretty sure I'll be all right . In fact , I'd be delighted to come over and celebrate your birthday with you . What time are you planning to start ?
Person1: Oh , good . If you could come around six thirty or seven o'clock , that would give us some time to chat a whit over a glass of wine before dinner .
Person2:That sounds fine . I'll be there around seven .
[A]: informal

[Q]: Person1: Did you do anything fun over the weekend ?
Person2:I didn't want to go out last weekend , so I decided to stay at home and watch a movie .
Person1: Why didn't you want to go out ?
Person2:I was very tired after working all week . Sometimes on the weekend I don't have enough energy to go out to a movie theater .
Person1: Did you download a movie or rent it at the store ?
Person2:I downloaded it so that I didn't have to remember to return it .
[A]:
formal