Definition: In this task, you will use your knowledge about language (and common sense) to determine what element the marked number refers to. The numbers are marked with two underlines around them, like: _ number _. Your answer should be chosen from the given text, and should not contain other words.
Input: The Doctor:  Ace , where do you think you 're going ?
Ace: Perivale .
The Doctor: Ah , yes , but by which route - the direct route with Glitz or the scenic route ? Well , do you fancy a quick trip ' round the twelve galaxies and then back to Perivale in time for tea ?
Ace: Ace !
The Doctor: But there are three rules . One : I 'm in charge .
Ace: Whatever you say , Professor .
The Doctor: _ Two _ : I 'm not the Professor . I 'm the Doctor .
Ace: Whatever you want .
The Doctor: And the third ... Well , I 'll think up the third by the time we get back to Perivale .

rules