With no explanation, label each line with "O", "building-airport", "organization-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-hospital" preceded by ":".
Flights
continued
until
artillery
attacks
by
North
Vietnamese
Army
and
Viet
Cong
military
units
on
Tan
Son
Nhut
Airport
rendered
airplane
flights
impossible
.
Flights:O
continued:O
until:O
artillery:O
attacks:O
by:O
North:organization-other
Vietnamese:organization-other
Army:organization-other
and:O
Viet:organization-other
Cong:organization-other
military:O
units:O
on:O
Tan:building-airport
Son:building-airport
Nhut:building-airport
Airport:building-airport
rendered:O
airplane:O
flights:O
impossible:O
.:O