A matchbox has a length of 4 cm, a width of 3 cm, and a height of 1 cm. How many square centimeters of cardboard are needed to make the outer box of such a matchbox?
一个火柴盒，长是4厘米，宽是3厘米，高是1厘米，制作这样一个火柴盒的外盒，至少需要多少平方厘米的硬纸板？
<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<gadget id="calculator">4 * 1</gadget>
<output>4</output>

<gadget id="calculator">12 + 4</gadget>
<output>16</output>

<gadget id="calculator">16 * 2</gadget>
<output>32</output>

<result>32</result>