The same as it is for you; to exist.
I see you must have meant something else. I mean, this is obvious, isn't it?
Hank
This answer does not go far enough, although Aristotle would no doubt agree in principle that a supreme good is only valid for what exists. The answer is given in the post above where Aristotle's own words from the Nicomachean Ethics show that the supreme good involves more than mere existence. We are complex on account of our ethical nature. In sum, Aristotle conceives of the good in two ways: the good involves more than one day, and more than one person. The last is the named political science, the first is anthropological and he sums it up with a nice aphorism:
The Good of man is the active exercise of his soul’s faculties in conformity with excellence or virtue.... Moreover this activity must occupy a complete lifetime; for one swallow does not make spring, nor does one fine day; and similarly one day or a brief period of happiness does not make a man supremely blessed and happy.
--bk. 1, ch. 7, sct. 1098a.
It's a good question and makes for worthwhile discussion.