Make a poker box with a length of 9 cm, a width of 6 cm, and a thickness of 15 cm. It is required that both ends can be opened and cards can be placed. And ask for the minimum number of square centimeters of paper to be used.
做一个长为9厘米，宽6厘米，厚15厘米的扑克牌盒子，要求两头均能打开，可放牌．并求最少要用多少平方厘米的纸．
<gadget id="calculator">9 * 6</gadget>
<output>54</output>

<gadget id="calculator">9 * 15</gadget>
<output>135</output>

<gadget id="calculator">6 * 15</gadget>
<output>90</output>

<gadget id="calculator">54 + 135 + 90</gadget>
<output>279</output>

<gadget id="calculator">279 * 2</gadget>
<output>558</output>

<gadget id="calculator">1 * 6 * 2</gadget>
<output>12</output>

<gadget id="calculator">558 + 12</gadget>
<output>570</output>

<result>570</result>