With no explanation, label each line with "location-GPE", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
It
was
from
Tan
Son
Nhut
Air
Base
that
the
last
U.S
.
Airman
left
South
Vietnam
in
March
1973
.
It:O
was:O
from:O
Tan:location-GPE
Son:location-GPE
Nhut:location-GPE
Air:location-GPE
Base:location-GPE
that:O
the:O
last:O
U.S:location-GPE
.:location-GPE
Airman:O
left:O
South:location-GPE
Vietnam:location-GPE
in:O
March:O
1973:O
.:O