With no explanation, label each line with "O", "person-athlete", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Four-time
winner
,
two-time
defending
champion
Roger
Federer
was
defeated
in
the
round
robin
stage
of
the
event
for
the
first
time
in
seven
consecutive
appearances
.
Four-time:O
winner:O
,:O
two-time:O
defending:O
champion:O
Roger:person-athlete
Federer:person-athlete
was:O
defeated:O
in:O
the:O
round:O
robin:O
stage:O
of:O
the:O
event:O
for:O
the:O
first:O
time:O
in:O
seven:O
consecutive:O
appearances:O
.:O