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'.

Person1: I want some envelopes please .
Person2:Do you want the large size , or the small size ?
Person1: The large size please . Do Have you any writing-paper ?
Person2:Yes , we do . I don't have any small pads . I only have large ones . Do you want a pad ?
Person1: Yes , please . And I want some glue .
Person2:A bottle of glue .
Person1: And I want a large box of chalk , too .
Person2:I only have small boxes . Do you want one ?
Person1: No , thank you .
Person2:Is that all ?
Person1: That's all , thank you .
Person2:What else do you want ?
Person1: I want my change .
formal