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 ":".
Between
19
November
and
15
December
1917
the
Austrians
launched
their
first
attack
on
the
unfinished
fortifications
.
Between:O
19:O
November:O
and:O
15:O
December:O
1917:O
the:O
Austrians:O
launched:O
their:O
first:O
attack:O
on:O
the:O
unfinished:O
fortifications:O
.:O