CREATE TABLE news_report (journalist_id DECIMAL, event_id DECIMAL, work_type TEXT)
CREATE TABLE journalist (journalist_id DECIMAL, name TEXT, nationality TEXT, age TEXT, years_working DECIMAL)
CREATE TABLE event (event_id DECIMAL, date TEXT, venue TEXT, name TEXT, event_attendance DECIMAL)

What is the nationality of the journalist with the largest number of years working?
SELECT nationality FROM journalist ORDER BY years_working DESC LIMIT 1
SELECT "nationality" FROM "journalist" ORDER BY "years_working" DESC NULLS LAST LIMIT 1