The school has to paint the walls and ceiling of a classroom. The length of the classroom is 9 meters, the width is 7 meters, and the height is 3 meters. The area after deducting the doors and windows is 12.5 square meters. If the labor cost per square meter is 0.4 yuan, how much is the total labor cost for painting this classroom?
学校要粉刷一间教室的四壁和天花板．教室的长9米，宽7米，高是3米，扣除门窗的面积12.5平方米，如果每平方米工价0.4元，粉刷这间教室共需工价多少元？
<gadget id="calculator">9 * 7</gadget>
<output>63</output>

<gadget id="calculator">9 * 3 * 2</gadget>
<output>54</output>

<gadget id="calculator">7 * 3 * 2</gadget>
<output>42</output>

<gadget id="calculator">42 - 12.5</gadget>
<output>29.5</output>

<gadget id="calculator">63 + 54 + 29.5</gadget>
<output>146.5</output>

<gadget id="calculator">0.4 * 146.5</gadget>
<output>58.6</output>

<result>58.6</result>