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 ":".
Until
1940
it
served
as
the
summer
residence
of
the
Estonian
president
Konstantin
Päts
.
Until:O
1940:O
it:O
served:O
as:O
the:O
summer:O
residence:O
of:O
the:O
Estonian:location-GPE
president:O
Konstantin:person-politician
Päts:person-politician
.:O