With no explanation, label each line with "O", "person-politician", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
After
consolidating
power
,
Klement
Gottwald
began
a
series
of
mass
purges
against
both
political
opponents
and
fellow
Communists
,
numbering
in
the
tens
of
thousands
.
After:O
consolidating:O
power:O
,:O
Klement:person-politician
Gottwald:person-politician
began:O
a:O
series:O
of:O
mass:O
purges:O
against:O
both:O
political:O
opponents:O
and:O
fellow:O
Communists:O
,:O
numbering:O
in:O
the:O
tens:O
of:O
thousands:O
.:O