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 ":".
Product
increased
gradually
until
the
turn
of
the
century
when
there
was
regular
demand
for
new
machines
.
Product:O
increased:O
gradually:O
until:O
the:O
turn:O
of:O
the:O
century:O
when:O
there:O
was:O
regular:O
demand:O
for:O
new:O
machines:O
.:O