{C} > 808487.pl
HOWTO (BLAH) START
  TRAVERSE (BLAH) START
    Found XYZ
  TRAVERSE (XYZ) START
    Found LA
  TRAVERSE (LA) START
  TRAVERSE (LA) FINISH
  TRAVERSE (XYZ) FINISH
  TRAVERSE (BLAH) FINISH
HOWTO (ASDF) START
  TRAVERSE (ASDF) START
    Found OOOOO
  TRAVERSE (OOOOO) START
  TRAVERSE (OOOOO) FINISH
  TRAVERSE (ASDF) FINISH
HOWTO (FOO) START
  TRAVERSE (FOO) START
    Found BAR
  TRAVERSE (BAR) START
    Found LA
  TRAVERSE (BAR) FINISH
    Found BLAH
    Found ASDF
  TRAVERSE (FOO) FINISH
HOWTO (FOO) FINISH
HOWTO (ASDF) FINISH
HOWTO (BLAH) FINISH

ANSWER = LA XYZ BLAH OOOOO ASDF BAR FOO