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 ":".
However
,
at
least
a
dozen
flight
crew
personnel
lost
their
lives
in
plane
crashes
.
However:O
,:O
at:O
least:O
a:O
dozen:O
flight:O
crew:O
personnel:O
lost:O
their:O
lives:O
in:O
plane:O
crashes:O
.:O