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 ":".
Withdrawals
began
in
January
1961
and
the
whole
class
had
disappeared
from
service
by
December
1962
.
Withdrawals:O
began:O
in:O
January:O
1961:O
and:O
the:O
whole:O
class:O
had:O
disappeared:O
from:O
service:O
by:O
December:O
1962:O
.:O