A classroom is 8 meters long, 6 meters wide, and 4 meters high. It is necessary to paint the roof and surrounding walls of the classroom. Excluding doors, windows and blackboards, the area is 30.5 square meters. How many square meters is the painted area?
一间教室长8米，宽6米，高4米，要粉刷教室的屋顶和四周墙壁，除去门窗和黑板面积30.5平方米，粉刷的面积是多少平方米？
<gadget id="calculator">8 * 4 * 2</gadget>
<output>64</output>

<gadget id="calculator">6 * 4 * 2</gadget>
<output>48</output>

<gadget id="calculator">8 * 6</gadget>
<output>48</output>

<gadget id="calculator">48 - 30.5</gadget>
<output>17.5</output>

<gadget id="calculator">64 + 48 + 17.5</gadget>
<output>129.5</output>

<result>129.5</result>