With no explanation, label each line with "O", "organization-sportsteam", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Since
their
debut
Italy
has
withdrawn
from
the
contest
a
number
of
times
.
Since:O
their:O
debut:O
Italy:organization-sportsteam
has:O
withdrawn:O
from:O
the:O
contest:O
a:O
number:O
of:O
times:O
.:O