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 ":".
However
,
its
effectiveness
for
constipation
is
poorly
supported
by
evidence
.
However:O
,:O
its:O
effectiveness:O
for:O
constipation:O
is:O
poorly:O
supported:O
by:O
evidence:O
.:O