With no explanation, label each line with "location-GPE", "O", "location-mountain", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
The
elevation
of
Saint
Petersburg
ranges
from
the
sea
level
to
its
highest
point
of
at
the
Orekhovaya
Hill
in
the
Duderhof
Heights
in
the
south
.
The:O
elevation:O
of:O
Saint:location-GPE
Petersburg:location-GPE
ranges:O
from:O
the:O
sea:O
level:O
to:O
its:O
highest:O
point:O
of:O
at:O
the:O
Orekhovaya:location-mountain
Hill:location-mountain
in:O
the:O
Duderhof:location-mountain
Heights:location-mountain
in:O
the:O
south:O
.:O