Calculation: 100+99-98-97+96+95-94-93+...+8+7-6-5+4+3-2-1.
计算：100+99-98-97+96+95-94-93+…+8+7-6-5+4+3-2-1．
<gadget id="calculator">4 - 2</gadget>
<output>2</output>

<gadget id="calculator">3 - 1</gadget>
<output>2</output>

<gadget id="calculator">2 + 2</gadget>
<output>4</output>

<gadget id="calculator">4 * 25</gadget>
<output>100</output>

<result>100</result>