The figure below shows a rectangular prism and a cube: A rectangular prism and a cube are drawn side by side. The length of the rectangle prism is 6 inches, the width is 5 over 6 inch, and its height is 1 and 2 over 6 inches. The cube has a side length of 1 over 6 inch. How many such cubes are required to completely pack the prism without any gap or overlap?