Putting together two identical half cylinders into a cylinder, the surface area is reduced by 200 square centimeters. It is known that the diameter of the base of this cylinder is 10 centimeters, so what is the surface area of the original half cylinder in square centimeters?
把两个完全一样的半圆柱拼成一个圆柱体，表面积就减少了200平方厘米，已知这个圆柱体的底面直径是10厘米，那么原来半圆柱的表面积是多少平方厘米？
<gadget id="calculator">200 / 2</gadget>
<output>100</output>

<gadget id="calculator">200 / 2 / 10 / 2</gadget>
<output>5</output>

<gadget id="calculator">5 ** 2</gadget>
<output>25</output>

<gadget id="calculator">3.14 * 25</gadget>
<output>78.5</output>

<gadget id="calculator">200 / 2 / 10</gadget>
<output>10</output>

<gadget id="calculator">3.14 * 10 * 5</gadget>
<output>157</output>

<gadget id="calculator">100 + 78.5 + 157</gadget>
<output>335.5</output>

<result>335.5</result>