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 ":".
Of
the
eighteen
gates
,
four
of
them
have
had
their
coating
system
replaced
.
Of:O
the:O
eighteen:O
gates:O
,:O
four:O
of:O
them:O
have:O
had:O
their:O
coating:O
system:O
replaced:O
.:O