The Children's Palace built an open-air swimming pool with a length of 28 meters, a width of 18 meters and a depth of 2 meters. How much area do you need to apply a layer of cement to the surrounding and bottom of the swimming pool?
少年宫修建了一个长28米，宽18米，深2米的露天游泳池．准备在游泳池的周围和底面抹一层水泥，需要抹多大面积？
<gadget id="calculator">28 * 18</gadget>
<output>504</output>

<gadget id="calculator">28 * 2</gadget>
<output>56</output>

<gadget id="calculator">18 * 2</gadget>
<output>36</output>

<gadget id="calculator">56 + 36</gadget>
<output>92</output>

<gadget id="calculator">92 * 2</gadget>
<output>184</output>

<gadget id="calculator">504 + 184</gadget>
<output>688</output>

<result>688</result>