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 ":".
President
Hoover
was
one
of
the
great
Americans
of
this
century
.
President:O
Hoover:person-politician
was:O
one:O
of:O
the:O
great:O
Americans:O
of:O
this:O
century:O
.:O