cube with a side length of 8 cm, dig a small hole of a cube with a side length of 4 cm in the middle of the top, and then dig a small hole with a side length of 2 cm in the middle of the bottom of the hole. The second small hole digging method is the same as the previous two, and the edge length is 1 cm, so what is the surface area of the finally obtained geometric object in square centimeters? (Note: It is to find the surface area of the big cube after digging 3 small cubes)
一个边长8厘米的正方体，在其上面正中位置向下挖一个棱长4厘米的正方体小洞，然后在洞的底面正中在向下挖一个棱长为2厘米的正方体的小洞，第三次小洞挖法与前两次相同，棱长是1厘米，那么最后得到的几何物体的表面积是多少平方厘米？(注：是求挖了3个小正方体之后的大正方体的表面积)
<gadget id="calculator">8 * 8 * 6</gadget>
<output>384</output>

<gadget id="calculator">4 * 4 * 4</gadget>
<output>64</output>

<gadget id="calculator">2 * 2 * 4</gadget>
<output>16</output>

<gadget id="calculator">1 * 1 * 4</gadget>
<output>4</output>

<gadget id="calculator">64 + 16 + 4</gadget>
<output>84</output>

<gadget id="calculator">384 + 84</gadget>
<output>468</output>

<result>468</result>