With no explanation, label each line with "O", "person-politician", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
His
parents
were
first
cousins
,
being
the
children
of
two
brothers
,
and
William
was
their
only
child
.
His:O
parents:O
were:O
first:O
cousins:O
,:O
being:O
the:O
children:O
of:O
two:O
brothers:O
,:O
and:O
William:person-politician
was:O
their:O
only:O
child:O
.:O