With no explanation, label each line with "O", "other-chemicalthing", "organization-company", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Pfizer
has
denied
that
sertraline
can
cause
such
effects
.
Pfizer:organization-company
has:O
denied:O
that:O
sertraline:other-chemicalthing
can:O
cause:O
such:O
effects:O
.:O