I like doing codewords, and we've got a book of them which we're slowly doing. (If you're not familiar with them, they contain all 26 letters of the alphabet, and each is given a number. You need to work out what letters represent which numbers.) Some are quite easy to get going with, but others much harder. Particularly when fewer than half the numbers/letters are known, it's very easy to make false assumptions. Anyway, here's one that I thought I'd try a new challenge with. After filling in the given letters, could I do the rest in my head? It was a medium-hard one to get going with, but yes, I did it. I did warn you that this post was a pure show-off.(Though I must confess that as I post this a few days later, I can't remember any of it ...!)