With no explanation, label each line with "O", "person-athlete", "organization-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Both
members
also
challenged
Bob
Backlund
for
the
WWF
Heavyweight
Championship
on
several
occasions
.
Both:O
members:O
also:O
challenged:O
Bob:person-athlete
Backlund:person-athlete
for:O
the:O
WWF:organization-other
Heavyweight:O
Championship:O
on:O
several:O
occasions:O
.:O