A cuboid block of wood is sawn from the middle to get two cubes with side lengths of 20 cm. What was the original surface area of the cuboid block?
一个长方体木块从中间锯开后，正好得到两个棱长是20厘米的正方体．这个长方体木块原来的表面积是多少？
<gadget id="calculator">20 * 2</gadget>
<output>40</output>

<gadget id="calculator">40 * 20 * 4</gadget>
<output>3_200</output>

<gadget id="calculator">20 * 20 * 2</gadget>
<output>800</output>

<gadget id="calculator">3_200 + 800</gadget>
<output>4_000</output>

<result>4_000</result>