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 ":".
Length
of
River
is
90
km
.
Length:O
of:O
River:O
is:O
90:O
km:O
.:O