note ambrus <p> As you're golfing, there are a few trivial modifications that can save a few characters (update: 4 characters). Omit the semicolons after the <c>sub</c> definitions and <c>for</c> loops, and change <c>($/*=16)%=O</c> to <c>$/=$/*16%O</c>. <readmore> <c> $|=print 3.2;sub O{8*($@-$_)+(1,4,5,6)[$:]}sub o{(-4,2,1,1)[$:]/O}while($,=++$@){for$:(0..3){ for (0..$@) {for$" (($/=1) ..$_){ $/=$/* 16%O} $,-=$/ *o}$, -=16** $_*o for-6..- 1}printf "%x",$,* 16%16} </c> </readmore> 534891 534891