With no explanation, label each line with "location-GPE", "O", "person-scholar", "art-broadcastprogram", "art-film", "art-music", "art-other", "art-painting", "art-writtenart" or "building-airport" preceded by ":".
During
his
studies
in
Mexico
he
was
mentored
by
Doctor
Ignacio
Chavez
Sanchez
(
one
of
the
most
prominent
physicians
in
Mexican
history
)
.
During:O
his:O
studies:O
in:O
Mexico:location-GPE
he:O
was:O
mentored:O
by:O
Doctor:O
Ignacio:person-scholar
Chavez:person-scholar
Sanchez:person-scholar
(:O
one:O
of:O
the:O
most:O
prominent:O
physicians:O
in:O
Mexican:O
history:O
):O
.:O