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 ":".
Usually
,
it
is
caused
by
either
food
shortage
or
disease
.
Usually:O
,:O
it:O
is:O
caused:O
by:O
either:O
food:O
shortage:O
or:O
disease:O
.:O