A room is 6 meters long, 4 meters wide, and 3.5 meters high. Now it is necessary to paint its four walls and top surface (doors and windows occupy 9 square meters without painting). How many square meters is the area to be painted in this room?
一间房间长6米，宽4米，高3.5米．现在要粉刷它的四壁和顶面(其中门窗占9平方米不粉刷)．这个房间要粉刷的面积是多少平方米？
<gadget id="calculator">6 * 4</gadget>
<output>24</output>

<gadget id="calculator">6 * 3.5</gadget>
<output>21</output>

<gadget id="calculator">4 * 3.5</gadget>
<output>14</output>

<gadget id="calculator">21 + 14</gadget>
<output>35</output>

<gadget id="calculator">35 * 2</gadget>
<output>70</output>

<gadget id="calculator">70 - 9</gadget>
<output>61</output>

<gadget id="calculator">24 + 61</gadget>
<output>85</output>

<result>85</result>