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
railroad
was
subsequently
operated
using
gravity
,
stationary
engines
and
horse
power
.
The:O
railroad:O
was:O
subsequently:O
operated:O
using:O
gravity:O
,:O
stationary:O
engines:O
and:O
horse:O
power:O
.:O