Cut a cylindrical piece of wood vertically along the diameter of the bottom surface into two pieces of the same shape and size. Given that the cut surface is a square with an area of 400 square centimeters, what is the surface area of the original wood in square centimeters?
把一根圆柱形木料沿着底面直径竖着切成形状、大小完全相同的两块．已知切面是一个面积为400平方厘米的正方形，原来木料的表面积是多少平方厘米．
<gadget id="calculator">20 / 2</gadget>
<output>10</output>

<gadget id="calculator">10 ** 2</gadget>
<output>100</output>

<gadget id="calculator">3.14 * 100 * 2</gadget>
<output>628</output>

<gadget id="calculator">3.14 * 20 * 20</gadget>
<output>1_256</output>

<gadget id="calculator">628 + 1_256</gadget>
<output>1_884</output>

<result>1_884</result>