After painting the surface of a cube with a side length of 3 cm red, and then sawing it into small cubes with a side length of 1 cm (no surplus, loss is not counted), then how many pieces have at least two sides painted red.
把棱长为3厘米的正方体的表面涂成红色后，再锯成棱长为1厘米的小正方体(无剩余，损耗不计)，那么至少有两面涂红色的有多少块．
<gadget id="calculator">27 - 6 - 1</gadget>
<output>20</output>

<result>20</result>