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 ":".
Tables
are
intended
to
be
kept
flat
,
but
any
given
table
may
have
its
own
slight
concave
or
convex
condition
,
adding
an
extra
challenge
.
Tables:O
are:O
intended:O
to:O
be:O
kept:O
flat:O
,:O
but:O
any:O
given:O
table:O
may:O
have:O
its:O
own:O
slight:O
concave:O
or:O
convex:O
condition:O
,:O
adding:O
an:O
extra:O
challenge:O
.:O