Three identical square cards, each measuring 2 inches by 2 inches, are placed on a table. The first card is laid down flat. The second card is placed directly on top of the first, but shifted 1 inch to the right and 1 inch up. The third card is placed directly on top of the second, but shifted another 1 inch to the right and 1 inch up. What is the total surface area (in square inches) covered by the overlapping cards?