With no explanation, label each line with "location-GPE", "person-soldier", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
Commander
Richard
Bolton
,
a
Canadian
,
who
must
lead
a
group
of
midget
submarines
in
an
attack
on
a
German
battleship
.
Commander:O
Richard:person-soldier
Bolton:person-soldier
,:O
a:O
Canadian:location-GPE
,:O
who:O
must:O
lead:O
a:O
group:O
of:O
midget:O
submarines:O
in:O
an:O
attack:O
on:O
a:O
German:location-GPE
battleship:O
.:O