There is a room with a length of 5 meters, a width of 4 meters, and a height of 3.5 meters. The roof and surrounding walls of the house need to be painted. The area excluding doors and windows is 18 square meters. How many square meters is the area to be painted?
有一房间，长5米，宽4米，高3.5米，要粉刷房子的顶面和四周墙壁，除去门窗的面积是18平方米，要粉刷的面积是多少平方米？
<gadget id="calculator">5 * 4</gadget>
<output>20</output>

<gadget id="calculator">5 * 3.5 * 2</gadget>
<output>35</output>

<gadget id="calculator">4 * 3.5 * 2</gadget>
<output>28</output>

<gadget id="calculator">28 - 18</gadget>
<output>10</output>

<gadget id="calculator">20 + 35 + 10</gadget>
<output>65</output>

<result>65</result>