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 ":".
His
father
was
a
doctor
,
and
his
mother
a
nurse
.
His:O
father:O
was:O
a:O
doctor:O
,:O
and:O
his:O
mother:O
a:O
nurse:O
.:O