Physics COnservation of energy problem..?? help?

[Mavic C]

Luke Skywalker joins some space friends in a health food bar. His empty drinking glass sits on a digital scale which correctly shows the force exerted on the glass by the scale. The glass has a hemispherical inside lower section of radius R and a cylindricial upper section of radius R and height R as shown. When a small ice cube is frozen to the rim at A, the scale reads 31 local force units (LFU = FN). When the ice cube is sliding without friction down the vertical wall at B, the scale reads 30 LFU. What is the scale reading when the ice cube, still without friction, slides over the bottom of the glass at C? (ANSWER IN LFU) [gravitation acceleration is unknown but constant]