The school has to paint the walls and ceiling of a classroom. It is known that the length of the classroom is 9 meters, the width is 6 meters, and the height is 3 meters. The area after deducting the doors and windows is 15 square meters. If the paint fee is 6 yuan per square meter, how much will it cost to paint the classroom?
学校要粉刷一间教室的四壁和天花．已知教室的长是9米，宽6米，高是3米，扣除门窗的面积15平方米，如果每平方米需要花6元涂料费，粉刷这个教室需要花费多少元？
<gadget id="calculator">9 * 6</gadget>
<output>54</output>

<gadget id="calculator">9 * 3</gadget>
<output>27</output>

<gadget id="calculator">6 * 3</gadget>
<output>18</output>

<gadget id="calculator">27 + 18</gadget>
<output>45</output>

<gadget id="calculator">45 * 2</gadget>
<output>90</output>

<gadget id="calculator">90 - 15</gadget>
<output>75</output>

<gadget id="calculator">54 + 75</gadget>
<output>129</output>

<gadget id="calculator">129 * 6</gadget>
<output>774</output>

<result>774</result>