With no explanation, label each line with "location-GPE", "O", "location-road/railway/highway/transit", "product-train", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting" or "art-writtenart" preceded by ":".
Because
of
its
low
maintenance
requirements
M62
locomotive
is
quite
popular
with
the
Korean
State
Railway
of
the
North
Korea
,
where
they
serve
not
only
on
non-electrified
lines
but
on
electrified
ones
as
well
.
Because:O
of:O
its:O
low:O
maintenance:O
requirements:O
M62:product-train
locomotive:O
is:O
quite:O
popular:O
with:O
the:O
Korean:location-road/railway/highway/transit
State:location-road/railway/highway/transit
Railway:location-road/railway/highway/transit
of:O
the:O
North:location-GPE
Korea:location-GPE
,:O
where:O
they:O
serve:O
not:O
only:O
on:O
non-electrified:O
lines:O
but:O
on:O
electrified:O
ones:O
as:O
well:O
.:O