The fresh milk box is 6.3 cm long, 4 cm wide and 10.5 cm high. To pack 24 boxes of fresh milk boxes into a box, what is the minimum square centimeter of paper used in the carton.
鲜奶盒长6.3厘米，宽4厘米，高10.5厘米．将24盒鲜奶盒包装成一箱，纸箱使用的纸最少是多少平方厘米．
<gadget id="calculator">6.3 * 3</gadget>
<output>18.9</output>

<gadget id="calculator">4 * 4</gadget>
<output>16</output>

<gadget id="calculator">18.9 * 16</gadget>
<output>302.4</output>

<gadget id="calculator">10.5 * 2</gadget>
<output>21</output>

<gadget id="calculator">18.9 * 21</gadget>
<output>396.9</output>

<gadget id="calculator">16 * 21</gadget>
<output>336</output>

<gadget id="calculator">302.4 + 396.9 + 336</gadget>
<output>1_035.3</output>

<gadget id="calculator">1_035.3 * 2</gadget>
<output>2_070.6</output>

<result>2_070.6</result>