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 ":".
Early
in
the
following
1981
season
,
Visger
underwent
his
first
knee
surgery
.
Early:O
in:O
the:O
following:O
1981:O
season:O
,:O
Visger:person-athlete
underwent:O
his:O
first:O
knee:O
surgery:O
.:O