Given the task definition and input, reply with output. 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: May I help you ?
Person2:I would like to return this book .
Person1: May I do anything else for you ?
Person2:I would also like to check out these books .
Person1: Will that be all ?
Person2:That ' s it .
Person1: Do you have your library card ?
Person2:Oh , yeah . Here you go .
Person1: Will that be all for today ?
Person2:That ' ll be all .
Person1: These books are due back in two weeks .
Person2:Thanks . Have a good one .
informal