With no explanation, label each line with "O", "event-sportsevent", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
1971
Buenos
Aires
1000
Kilometers
was
the
opening
round
of
the
1971
International
Championship
for
Makes
season
.
The:O
1971:O
Buenos:event-sportsevent
Aires:event-sportsevent
1000:event-sportsevent
Kilometers:event-sportsevent
was:O
the:O
opening:O
round:O
of:O
the:O
1971:O
International:event-sportsevent
Championship:event-sportsevent
for:event-sportsevent
Makes:event-sportsevent
season:O
.:O