With no explanation, label each line with "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport", "building-hospital" or "building-hotel" preceded by ":".
Lessons
learned
from
these
disasters
have
led
to
safer
football
stadiums
.
Lessons:O
learned:O
from:O
these:O
disasters:O
have:O
led:O
to:O
safer:O
football:O
stadiums:O
.:O