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
rivalry
began
to
heat
up
in
the
early
2000s
.
The:O
rivalry:O
began:O
to:O
heat:O
up:O
in:O
the:O
early:O
2000s:O
.:O