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See If You Can Tell Which Olsen Sister Is Which In This Throwback Photo

Can you name all four of these Olsen sisters?

Unless you've been living under a rock for the past three decades, you know the Olsen Twins. And if you've been paying even a modicum of attention to pop culture recently, you might even know who Elizabeth Olsen is. But did you know there are actually FOUR Olsen sisters? Yeah, four -- plus two boys.

See, Mary-Kate and Ashley, who became permanent members of the zeitgeist thanks to their adorable shared turn as Michelle Tanner in "Full House" and subsequent twin-tastic family film and TV fare (all of which still hold up, BTW), were born second after their brother Trent. Then came Elizabeth, and after the original Olsen parents split and the father remarried, Taylor and Jake rounded out the family.

So, while MK, Ashley and Lizzie might get the most play in popularity, there are a total of six Olsen siblings scampering about, and some of them are hard to tell apart -- namely, the sisters.

It's hard to even pick out which Olsen is which in this throwback photo Elizabeth shared on Friday (Aug. 21).

Can you guess the whole line-up? We're stumped, as always, on those last two.

OK, OK, so it doesn't take a genius to figure it out, but the point here is that all four of these Olsen girls are alike, and if one of 'em ever commits a crime, all her sisters can come in and joggle those line-up results so hard. Not that we're encouraging such a thing, of course.