From a cube with edge length 15, cut off small cubes with edge lengths 1, 2, 3, 4, 5, 6, 7, and 8, what is the minimum surface area of the remaining part of the block?
从一个棱长是15的正方体木块中，截去棱长分别是1，2，3，4，5，6，7，8的小正方体，这个木块剩下部分的表面积最小是多少？
<gadget id="calculator">15 * 15 * 6</gadget>
<output>1_350</output>

<gadget id="calculator">7 * 7 * 2</gadget>
<output>98</output>

<gadget id="calculator">1_350 - 98</gadget>
<output>1_252</output>

<result>1_252</result>