user: Question: What is the goal difference sum that has goals against smaller than 33, draws larger than 13?
Columns: ['Position', 'Club', 'Played', 'Points', 'Wins', 'Draws', 'Losses', 'Goals for', 'Goals against', 'Goal Difference']
Types: ['real', 'text', 'real', 'text', 'real', 'real', 'real', 'real', 'real', 'real']
Sample row: [1.0, 'CD Castellón', 38.0, '51+13', 21.0, 9.0, 8.0, 49.0, 29.0, 20.0]
SQL:

assistant: SELECT SUM("Goal Difference") FROM "Table" WHERE "Goals against" < 33.0 AND "Draws" > 13.0;