With no explanation, label each line with "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport", "building-hospital" or "building-hotel" preceded by ":".
An
optimal
capacity
for
concerts
is
75,000
fans
.
An:O
optimal:O
capacity:O
for:O
concerts:O
is:O
75,000:O
fans:O
.:O