With no explanation, label each line with "location-GPE", "O", "art-painting", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
The
Portrait
of
the
Four
Tetrarchs
is
a
porphyry
sculpture
group
of
four
Roman
emperors
dating
from
around
300
AD
.
The:O
Portrait:O
of:O
the:O
Four:art-painting
Tetrarchs:art-painting
is:O
a:O
porphyry:O
sculpture:O
group:O
of:O
four:O
Roman:location-GPE
emperors:O
dating:O
from:O
around:O
300:O
AD:O
.:O