instruction:
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'.
question:
Person1: Who ' s this ? your girl-friend ?
Person2:No , it ' s my sister .
Person1: How old is she ?
Person2:She ' s 18 .
Person1: She is tall ?
Person2:Yes , she is .
Person1: And she is thin , isn ' t she ?
Person2:Well , just a little thin .
answer:
formal

question:
Person1: How nice these sunglasses are !
Person2:Yes , they are the latest designs . Would you like to try them on ?
Person1: I want to try on this pair .
Person2:The round shape pair ?
Person1: That's right .
Person2:I think it suits you well .
Person1: I agree , how much ?
Person2:120 yuan .
Person1: It's not expensive . OK . I'll take them .
answer:
informal

question:
Person1: Hey , Jack , I'd better go now .
Person2:Is your boss coming by ?
Person1: Right ! And I have to finish the report by 5:30 p . m .
Person2:Okay . Get back to your work , and call me back this evening .
Person1: Okay , no problem . Bye !
Person2:Bye !
answer:
formal