With no explanation, label each line with "location-GPE", "O", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart", "building-airport" or "building-hospital" preceded by ":".
When
Mexico
achieved
its
independence
in
1821
,
the
Mexican
political
life
was
altered
by
constant
struggles
between
Liberals
and
Conservatives
.
When:O
Mexico:location-GPE
achieved:O
its:O
independence:O
in:O
1821:O
,:O
the:O
Mexican:location-GPE
political:O
life:O
was:O
altered:O
by:O
constant:O
struggles:O
between:O
Liberals:O
and:O
Conservatives:O
.:O