You will be given a definition of a task first, then some input of the task.
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: There are things that are actually even smaller than atoms .
Person2:What are those ?
Person1: They are the things that make up the atom , such as electrons and protons .
Person2:Is there anything that is smaller than electrons and protons ?
Person1: Of course there is . Things can be divided and broken down into indefinitely small parts if we can .
Person2:I really don't want to know about this . Physics gives me a headache .
Output:
informal