A classroom with a length of 8 meters, a width of 6 meters, and a height of 4 meters has a door and window area of 15 square meters. How much area will the walls and roof be painted?
一间长8米，宽6米，高4米的教室，门窗面积是15平方米．要粉刷四壁和屋顶的面积是多少？
<gadget id="calculator">8 * 6</gadget>
<output>48</output>

<gadget id="calculator">6 * 4 * 2</gadget>
<output>48</output>

<gadget id="calculator">8 * 4 * 2</gadget>
<output>64</output>

<gadget id="calculator">48 + 48 + 64</gadget>
<output>160</output>

<gadget id="calculator">160 - 15</gadget>
<output>145</output>

<result>145</result>