How long can a short story be?

How long can a short story be?
Hi, I have you write a short story for my creative writing class, we have to present it. But I don’t know how long is to long, and how short is to short. Does anyone have any recomendations?

Right from Wikipedia

Determining what exactly separates a short story from longer fictional formats is problematic. A classic definition of a short story is that one should be able to be read it in one sitting, a point most notably made in Edgar Allan Poe’s essay “The Philosophy of Composition” (1846). Other definitions place the maximum word length at 7,500 words. In contemporary usage, the term short story most often refers to a work of fiction no longer than 20,000 words and no shorter than 1,000.