Use cardboard to make a cuboid whose length, width and height are 7cm, 5cm and 3cm respectively. What is the sum of the lengths of the sides of the cuboid in cm?
用硬纸板做一个长、宽、高分别是7cm、5cm、3cm的长方体，这个长方体的棱长总和是多少cm．
<gadget id="calculator">7 + 5 + 3</gadget>
<output>15</output>

<gadget id="calculator">15 * 4</gadget>
<output>60</output>

<result>60</result>