note MeowChow Ok, here's my current solution at 192 chars. <code> sub a{$#_?(sort{length$a<=>length$b}map{my$s=$_;my@l=grep{$s ne $_}@_;map{my$t=$_;my@m=grep{$t ne $_}@l;a(i($s,$t),@m)}@l}@_)[0]:pop} sub i{($_,$t)=@_;chop$t while!s/\Q$t\E$/$_[1]/&&''ne$t;$_;} print a qw(logger gerbil log analog); print "\n"; print a qw(GATTACA ATTACA GATT AAGAT CCC); </code> <b>update1</b>: trimmed another 4 chars from the <code>i</code> sub, and stopped clobbering globals: <code> sub i{my($s,$t)=@_;chop$t while$s!~s/\Q$t\E$/$_[1]/;$s} </code> ... if we're clobbering $_, we can trim another 5: <code> sub i{($_,$t)=@_;chop$t while!s/\Q$t\E$/$_[1]/;$_} </code> <b>update2</b>: 163 chars, strict and global-clean, all in one sub, named <code>assemble</code> (or 156 if it's named <code>a</code>): <code> sub assemble{$#_?(sort{length$a<=>length$b}map{my$s=$_;my@l=grep$s ne$_,@_;map{my($t,$u)=($s,$_);my@m=grep$u ne$_,@l;chop$u while$t!~s/\Q$u\E$/$_/;assemble($t,@m)}@l}@_)[0]:pop} </code> <pre> <a href="/index.pl?node=MeowChow"> MeowChow </a> s aamecha.s a..a\u$&owag.print</pre> 77183 77183