With no explanation, label each line with "O", "product-train", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Passenger
information
systems
are
fitted
in
every
car
and
on
the
outside
of
class
168/2
cars
.
Passenger:O
information:O
systems:O
are:O
fitted:O
in:O
every:O
car:O
and:O
on:O
the:O
outside:O
of:O
class:product-train
168/2:product-train
cars:product-train
.:O