With no explanation, label each line with "O", "organization-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Much
of
the
Greek
army
retreated
,
before
the
Spartans
and
Thespians
who
had
continued
to
block
the
pass
were
surrounded
and
killed
.
Much:O
of:O
the:O
Greek:organization-other
army:organization-other
retreated:O
,:O
before:O
the:O
Spartans:organization-other
and:O
Thespians:organization-other
who:O
had:O
continued:O
to:O
block:O
the:O
pass:O
were:O
surrounded:O
and:O
killed:O
.:O