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 ":".
The
cloudy
conditions
meant
that
none
of
the
aircraft
engaged
could
be
confirmed
as
destroyed
.
The:O
cloudy:O
conditions:O
meant:O
that:O
none:O
of:O
the:O
aircraft:O
engaged:O
could:O
be:O
confirmed:O
as:O
destroyed:O
.:O