How many pomegranate seeds did Persephone eat anyway?

Because I like summer so much (even when it's been muggy, as in NYC recently), I found myself thinking: Why did Persephone have to eat those six pomegranate seeds when Hades was holding her prisoner in the Underworld, according to the Greek myth, causing us to have six green months and six barren months?  Couldn't she at least have eaten fewer seeds, if not fasted altogether?

But when I checked online, I found a startling lack of consensus regarding just how many seeds she is supposed to have eaten.  It appears alternatively to have been one, three, four, or six.