With no explanation, label each line with "O", "location-mountain", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
summits
of
Snowdon
and
Garnedd
Ugain
are
surrounded
by
cwms
,
rounded
valleys
scooped
out
by
glaciation
.
The:O
summits:O
of:O
Snowdon:location-mountain
and:O
Garnedd:location-mountain
Ugain:location-mountain
are:O
surrounded:O
by:O
cwms:O
,:O
rounded:O
valleys:O
scooped:O
out:O
by:O
glaciation:O
.:O