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 ":".
While
there
was
still
a
significant
number
of
steam
locomotives
in
the
yard
,
railway
preservationists
began
buying
the
better
examples
from
the
late
1960s
in
order
to
restore
them
to
working
order
.
While:O
there:O
was:O
still:O
a:O
significant:O
number:O
of:O
steam:O
locomotives:O
in:O
the:O
yard:O
,:O
railway:O
preservationists:O
began:O
buying:O
the:O
better:O
examples:O
from:O
the:O
late:O
1960s:O
in:O
order:O
to:O
restore:O
them:O
to:O
working:O
order:O
.:O