hahaha...in past time i like to fill the sudoku umm i think it was 9x9..enaugh to make my head burned..hehe
I love it but get so annoyed when the puzzles aren't "solvable". There should only ever be one right answer but one book I had would frequently have the the last few cells completely interchangeable. Frustrating! I have a good android game, some good ones on iPad and our local paper does them too. Hard/Expert works for me.