classroom is 10m long, 8m wide, 4m high, and the total area of doors and windows is 15m**2. To paint this classroom, what is the area to be painted in m**2?
一间教室长10m，宽8m，高4m，门窗总面积15m**2，要粉刷这间教室，粉刷的面积是多少m**2？
<gadget id="calculator">8 * 10</gadget>
<output>80</output>

<gadget id="calculator">10 * 4</gadget>
<output>40</output>

<gadget id="calculator">8 * 4</gadget>
<output>32</output>

<gadget id="calculator">40 + 32</gadget>
<output>72</output>

<gadget id="calculator">72 * 2</gadget>
<output>144</output>

<gadget id="calculator">144 - 15</gadget>
<output>129</output>

<gadget id="calculator">80 + 129</gadget>
<output>209</output>

<result>209</result>