With no explanation, label each line with "O", "event-other", "art-music", "product-software", "person-other", "art-broadcastprogram", "art-film", "art-other", "art-painting" or "art-writtenart" preceded by ":".
To
promote
``
Why
``
,
Taeyeon
held
an
event
called
``
Countdown
Night
``
prior
to
the
song
's
release
on
Naver
's
V
app
.
To:O
promote:O
``:O
Why:art-music
``:O
,:O
Taeyeon:person-other
held:O
an:O
event:O
called:O
``:O
Countdown:event-other
Night:event-other
``:O
prior:O
to:O
the:O
song:O
's:O
release:O
on:O
Naver:product-software
's:product-software
V:product-software
app:O
.:O