With no explanation, label each line with "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport", "building-hospital" or "building-hotel" preceded by ":".
Around
and
on
top
of
the
factory
buildings
,
there
was
a
test
track
over
1
km
long
.
Around:O
and:O
on:O
top:O
of:O
the:O
factory:O
buildings:O
,:O
there:O
was:O
a:O
test:O
track:O
over:O
1:O
km:O
long:O
.:O