>I failed to solve this one, 14 years ago, and actually slapped my forehead hard when I saw the solution.
Unlike many other puzzles, I remember solving this rather quickly - but only because I happened to do some testing on squared paper!
Difference in opinions hath cost many millions of lives: for instance, whether flesh be bread, or bread be flesh; whether whistling be a vice or a virtue; whether it be better to kiss a post, or throw it into the fire... (from Gulliver's Travels)
