A piece of rectangular iron sheet with a length of 40 cm and a width of 30 cm. Cut off a square with a side length of 4 cm from each of the four corners and weld it into a rectangular iron box (the loss of joints is not counted, and the cut ones are not used). What is the volume in milliliters?
一块长方形铁皮，长40厘米，宽30厘米，从四个角上各切去一个边长为4厘米的正方形，焊接成长方体铁盒(接头损耗不计，切去的不用)，这个长方体铁盒的容积是多少毫升？
<gadget id="calculator">4 * 2</gadget>
<output>8</output>

<gadget id="calculator">40 - 8</gadget>
<output>32</output>

<gadget id="calculator">30 - 8</gadget>
<output>22</output>

<gadget id="calculator">32 * 22 * 4</gadget>
<output>2_816</output>

<result>2_816</result>