Fortune Cookies I

You buy a package of $n$ fortune cookies and open each one to see the fortune slip inside. The first slip says "a maximum of $0$ of these $n$ slips tell the truth." The next slip says "a maximum of $1$ of these $n$ slips tell the truth.", and so on, until the last slip, which says "a maximum of $n-1$ of these $n$ slips tell the truth." How many of these slips are telling the truth when $n = 1000$?