In a cube of cast iron with a base area of 324 square centimeters, use the opposite sides as the base to dig out the largest cylinder, and then paint the remaining cast iron surface. What is the painted area?
在底面积为324平方厘米的正方体铸铁中，以相对的两面为底，挖出一个最大的圆柱形，然后在剩下的铸铁表面上涂上油漆，求涂漆的面积是多少？
<gadget id="calculator">18 * 18 * 6</gadget>
<output>1_944</output>

<gadget id="calculator">18 / 2</gadget>
<output>9</output>

<gadget id="calculator">9 ** 2</gadget>
<output>81</output>

<gadget id="calculator">3.14 * 81 * 2</gadget>
<output>508.68</output>

<gadget id="calculator">1_944 - 508.68</gadget>
<output>1_435.32</output>

<gadget id="calculator">3.14 * 18 * 18</gadget>
<output>1_017.36</output>

<gadget id="calculator">1_435.32 + 1_017.36</gadget>
<output>2_452.68</output>

<result>2_452.68</result>