With no explanation, label each line with "O", "event-other", "organization-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
The
World
Clean
Air
Congress
,
first
organized
by
IUAPPA
in
1966
,
is
held
every
two
or
three
years
.
The:O
World:event-other
Clean:event-other
Air:event-other
Congress:event-other
,:O
first:O
organized:O
by:O
IUAPPA:organization-other
in:O
1966:O
,:O
is:O
held:O
every:O
two:O
or:O
three:O
years:O
.:O