With no explanation, label each line with "O", "person-actor", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
In
January
1959
Richard
Burton
signed
to
play
the
male
lead
.
In:O
January:O
1959:O
Richard:person-actor
Burton:person-actor
signed:O
to:O
play:O
the:O
male:O
lead:O
.:O