A cube is a box with a side length of 40 cm. What is the minimum square centimeter of cardboard needed to make this carton.
一个正方体纸盒，棱长是40厘米．做这个纸盒至少需要硬纸板多少平方厘米．
<gadget id="calculator">40 * 40 * 6</gadget>
<output>9_600</output>

<result>9_600</result>