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 ":".
It
is
the
midpoint
of
the
railway
line
.
It:O
is:O
the:O
midpoint:O
of:O
the:O
railway:O
line:O
.:O