note merlyn 118 chars: <code> sub state { 1&index" AKALCAARAZCOCTDCDEFLGAHIIAIDILINKSKTKYLAMAMDMEMIMNNCMOMSMTOHNDNENHNJNMPANVNYOKORRISCSDTNTXUTVAVTWAWIWVWY",pop } </code> And it's 117 chars if you replace pop with $_, as the original rules ask. <p> The character string was constructed to ensure that a valid state would never match a non-valid boundary. It was easier than I thought: <code> #!/usr/bin/perl use strict; $|++; my @states = qw( AK AL AR AZ CA CO CT DC DE FL GA HI IA ID IL IN KS KT KY LA MA MD ME MI MN MO MS MT NC ND NE NH NJ NM NV NY OH OK OR PA RI SC SD TN TX UT VA VT WA WI WV WY ); my %states = map { $_ => 1 } @states; try("", \@states); sub try { print "try: $_[0] @{$_[1]}\n"; my $prefix = shift; my @later = @{+shift}; unless (@later) { print "WINNER: $prefix\n"; exit; } for my $i (0..$#later) { my $prefix2 = "$prefix$later[$i]"; if (length $prefix2 < 3 or not $states{substr($prefix2, -3, 2)}) { ## worth recursing try($prefix2, [@later[0..$i-1, $i+1..$#later]]); } } } </code> <p>-- <a href="http://www.stonehenge.com/merlyn/">Randal L. Schwartz, Perl hacker</a></p> 86047 86047