A cuboid wooden box (without a cover), whose length, width, and height are 40cm, 30cm, and 50cm, respectively, if you want to paint it with green paint, how many square decimeters is the painted area?
一个长方体木箱(没有盖)，长、宽、高分别是40cm、30cm和50cm，如果想为它刷上绿色的油漆，涂油漆的面积是多少平方分米．
<gadget id="calculator">40 / 10</gadget>
<output>4</output>

<gadget id="calculator">30 / 10</gadget>
<output>3</output>

<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<gadget id="calculator">50 / 10</gadget>
<output>5</output>

<gadget id="calculator">3 * 5</gadget>
<output>15</output>

<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<gadget id="calculator">12 + 15 + 20</gadget>
<output>47</output>

<gadget id="calculator">47 * 2</gadget>
<output>94</output>

<gadget id="calculator">94 - 12</gadget>
<output>82</output>

<result>82</result>