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 ":".
By
nightfall
,
60,000
soldiers
had
joined
the
revolution
.
By:O
nightfall:O
,:O
60,000:O
soldiers:O
had:O
joined:O
the:O
revolution:O
.:O