With no explanation, label each line with "O", "location-road/railway/highway/transit", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
Proposals
of
the
construction
of
the
Kerch
Strait
bridge
were
considered
as
early
as
1903
.
Proposals:O
of:O
the:O
construction:O
of:O
the:O
Kerch:location-road/railway/highway/transit
Strait:location-road/railway/highway/transit
bridge:location-road/railway/highway/transit
were:O
considered:O
as:O
early:O
as:O
1903:O
.:O