An auditorium is 20 meters long, 15 meters wide, and 4 meters high. The area of doors and windows is 28 square meters. If you want to paint the surrounding area and the ceiling, the average cost is 3.2 yuan per square meter. How much is the minimum cost?
一个礼堂长20米，宽15米，高4米，门窗面积是28平方米，如果要粉刷四周和顶棚，平均每平方米花费3.2元，那么至少花费多少钱？
<gadget id="calculator">20 * 15</gadget>
<output>300</output>

<gadget id="calculator">20 * 4 * 2</gadget>
<output>160</output>

<gadget id="calculator">15 * 4 * 2</gadget>
<output>120</output>

<gadget id="calculator">120 - 28</gadget>
<output>92</output>

<gadget id="calculator">300 + 160 + 92</gadget>
<output>552</output>

<gadget id="calculator">552 * 3.2</gadget>
<output>1_766.4</output>

<result>1_766.4</result>