You have to fill the squares with the numbers 0-9 and the letters A-F.

You can only have the letters and numbers ONCE in each row, column, and square.


I've been working on it for the best part of three days now...and I've had to startagain 5 times!!!

HEALTH WARNING: These are the type of things that once you start you think to yourself "I must finish it". And you don't stop until you do finish it.

Edit:

And you also end up talking to yourself...a lot...