ido: how to recall previous input?

[Kai Großjohann]

Let's say I want to create two directories, /foo/bar and /foo/baz.
With the normal prompting, I do M-x make-directory RET /foo/bar RET,
then M-x make-directory RET again, then M-p to recall previous input,
then delete the trailing r and replace it with z.

I haven't found out how to do the M-p thing (or something similar to
it) with ido.

(Ido has its own binding for M-p and I have no idea what that does
:-)  I've done C-h f on it, and I've tried it, but still, no idea.)
-- 
A turnip curses Elvis