FOO BAR BLAH ASDF
BAR LA
BLAH XYZ
ASDF OOOOO
LA
XYZ LA
OOOOO

##</code><code>##

Simple path down:
BLAH -> XYZ -> LA

But now we look back up:

LA   <- BAR  <- FOO
XYZ  <- BLAH <- FOO
BLAH <- FOO

And now we look back down again
FOO -> ASDF -> OOOOO

And finally back up
ASDF <- FOO

##</code><code>##

BLAH
XYZ
LA
BAR
FOO
ASDF
OOOOO

##</code><code>##

LA -> XYZ -> BLAH -> BAR -> OOOOO -> ASDF -> FOO
LA -> XYZ -> BLAH -> OOOOO -> ASDF -> BAR -> FOO
LA -> XYZ -> BLAH -> OOOOO -> BAR -> ASDF -> FOO