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 ":".
The
average
altitude
of
the
town
is
about
.
The:O
average:O
altitude:O
of:O
the:O
town:O
is:O
about:O
.:O