With no explanation, label each line with "O", "person-artist/author", "person-other", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
It
is
well
known
that
Vargas
was
a
close
friend
and
a
frequent
house
guest
of
Frida
Kahlo
and
her
husband
Diego
Rivera
.
It:O
is:O
well:O
known:O
that:O
Vargas:person-artist/author
was:O
a:O
close:O
friend:O
and:O
a:O
frequent:O
house:O
guest:O
of:O
Frida:person-other
Kahlo:person-other
and:O
her:O
husband:O
Diego:person-other
Rivera:person-other
.:O