With no explanation, label each line with "location-GPE", "O", "person-politician", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
In
his
first
letter
,
Isaac
II
referred
to
Barbarossa
simply
as
the
``
King
of
Germany
``
.
In:O
his:O
first:O
letter:O
,:O
Isaac:person-politician
II:person-politician
referred:O
to:O
Barbarossa:person-politician
simply:O
as:O
the:O
``:O
King:O
of:O
Germany:location-GPE
``:O
.:O