That's exactly how I solved it on a bus trip yesterday.
But there is another solution, not so obvious, which may be what Jer was looking for (as the problem is D4).
blackjack
<a href="http://c.casalemedia.com/c?s=51816&f=3&id=0" target="_blank"><img src="http://as.casalemedia.com/s?s=51816&u=http://perplexus.info&f=3&id=0&if=0" width="120" height="600" border="0"></a>
flooble's webmaster puzzle
re: easy - spoiler
