Elizabeth brought a box of donuts to share. There are​ two-dozen (24) donuts in the​ box, all identical in​ size, shape, and color.  Six are​ jelly-filled, 99 are​ lemon-filled, and 99 are​ custard-filled. You randomly select one​ donut, eat​ it, and select another donut. Find the probability of selecting two custard​-filled donuts in a row.