With no explanation, label each line with "O", "other-medical", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Tretinoin
is
the
least
expensive
of
the
topical
retinoids
and
is
the
most
irritating
to
the
skin
,
whereas
adapalene
is
the
least
irritating
but
costs
significantly
more
.
Tretinoin:other-medical
is:O
the:O
least:O
expensive:O
of:O
the:O
topical:other-medical
retinoids:other-medical
and:O
is:O
the:O
most:O
irritating:O
to:O
the:O
skin:O
,:O
whereas:O
adapalene:other-medical
is:O
the:O
least:O
irritating:O
but:O
costs:O
significantly:O
more:O
.:O