The surface of a cuboid wooden block is covered with red paint. After cutting it into small cubes with a side length of 1 cm, there are only 3 blocks that are not painted on all sides. What is the surface area of this cuboid block in square centimetres?
一个长方体木块表面涂满了红漆，把它全部切成棱长1厘米的小正方体以后，各个面上都没有漆的只有3块．这个长方体木块的表面积是多少平方厘米？
<gadget id="calculator">3 * 3 * 2</gadget>
<output>18</output>

<gadget id="calculator">3 * 5 * 4</gadget>
<output>60</output>

<gadget id="calculator">18 + 60</gadget>
<output>78</output>

<result>78</result>