On Wed, Jul 11, 2007 at 01:38:11PM -0400, Chiao-Lun Cheng wrote: > I've pasted a brute force solution that uses Peter Norvig's > tree-search function at > > http://paste.lisp.org/display/44376 Cool. I took the liberty of posting it to the xkcd forum. Hope that's okay. http://forums.xkcd.com/viewtopic.php?t=7532 -- Larry