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 ":".
A
follow-up
contract
,
placed
during
September
1965
,
ordered
140
more
aircraft
.
A:O
follow-up:O
contract:O
,:O
placed:O
during:O
September:O
1965:O
,:O
ordered:O
140:O
more:O
aircraft:O
.:O