To decorate a living room, the length is 4 meters, the width is 2.5 meters, the height is 3 meters, and the door and window area is 10 square meters. If you paint it, the walls and the ceiling, how many square meters should be painted at least?
装修一间居室，长是4米，宽是2.5米，高是3米，门窗面积10平方米，在它和四壁和顶棚刷油漆，至少需刷油漆多少平方米？
<gadget id="calculator">4 * 2.5</gadget>
<output>10</output>

<gadget id="calculator">4 * 3</gadget>
<output>12</output>

<gadget id="calculator">2.5 * 3</gadget>
<output>7.5</output>

<gadget id="calculator">10 + 12 + 7.5</gadget>
<output>29.5</output>

<gadget id="calculator">29.5 * 2</gadget>
<output>59</output>

<gadget id="calculator">59 - 10 - 10</gadget>
<output>39</output>

<result>39</result>