Eric baked a berry pie. The recipe called for 5 ounces of blackberries, 8 ounces of raspberries, and 9 ounces of strawberries. In the supermarket, he only found 12-ounce containers of berries. He bought 1 container of each kind of berry. After he baked the pie, how many ounces of berries did Eric have left?

He used 5+6+9 = ____ ounces, so ...