With no explanation, label each line with "O", "location-road/railway/highway/transit", "product-train", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
WDS-4
shunting
locos
based
all
over
Northern
Railway
are
sent
here
for
periodical
maintenance
.
WDS-4:product-train
shunting:O
locos:O
based:O
all:O
over:O
Northern:location-road/railway/highway/transit
Railway:location-road/railway/highway/transit
are:O
sent:O
here:O
for:O
periodical:O
maintenance:O
.:O