Take a look at this image. How many squares can you count? The answer is a bit tricky, according to Readers Digest, so go ahead and look carefully.

Ready?

Did you guess 9? Or 13? Or 14? Sorry, but not quite right.

The key is that each of the small squares can be combined to make bigger squares. The whole thing, in fact, is one square in itself.

The creator of the puzzle claims that there are 19 squares pictured—that’s the solution that accompanies the illustration.

Olena Siedykh, Alamy Stock Vector

But, to underscore how subtly tricky this one is, other geometry whizzes have been able to find 23 squares by combining the smallest squares in the middle. Give it a second look, and see if you can find all the different iterations. And let us know if you can find more than 23!