Maggie baked a berry pie. The recipe called for 6 ounces of blackberries, 9 ounces of raspberries, and 5 ounces of strawberries. In the supermarket, she only found 12-ounce containers of berries. She bought 1 container of each kind of berry. After she baked the pie, how many ounces of berries did Maggie have left?