user: Question: What is the nationality of the elector withe the Cardinalatial order and title of Cardinal-priest of Ss. XII Apostoli?
Columns: ['Elector', 'Nationality', 'Cardinalatial order and title', 'Elevated', 'Elevator']
Types: ['text', 'text', 'text', 'text', 'text']
Sample row: ['Pietro Corsini', 'Florentine', 'Cardinal-bishop of Porto e Santa Rufina', '1370, June 7', 'Urban V']
SQL:

assistant: SELECT "Nationality" FROM "Table" WHERE "Cardinalatial order and title" = 'Cardinal-priest of Ss. XII Apostoli';