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 ":".
Regarded
politically
unreliable
,
he
was
put
under
the
secret
police
surveillance
.
Regarded:O
politically:O
unreliable:O
,:O
he:O
was:O
put:O
under:O
the:O
secret:O
police:O
surveillance:O
.:O