moon cake box is 20 cm long, 18 cm wide, and 15 cm high. Now it is necessary to paste label paper around it. What is the area of this label paper in square centimeters?
一个月饼盒长20厘米，宽18厘米，高15厘米，现在要在它的四周贴上商标纸，这张商标纸的面积是多少平方厘米？
<gadget id="calculator">20 * 15</gadget>
<output>300</output>

<gadget id="calculator">18 * 15</gadget>
<output>270</output>

<gadget id="calculator">300 + 270</gadget>
<output>570</output>

<gadget id="calculator">570 * 2</gadget>
<output>1_140</output>

<result>1_140</result>