Calculation: 9999+9997+...+1999+1997+1995.
计算：9999+9997+…+1999+1997+1995．
<gadget id="calculator">1_995 + 9_999</gadget>
<output>11_994</output>

<gadget id="calculator">9_999 - 1_995</gadget>
<output>8_004</output>

<gadget id="calculator">8_004 / 2</gadget>
<output>4_002</output>

<gadget id="calculator">4_002 + 1</gadget>
<output>4_003</output>

<gadget id="calculator">4_003 / 2</gadget>
<output>4_003/2 = around 2_001.5</output>

<gadget id="calculator">11_994 * (4_003/2)</gadget>
<output>24_005_991</output>

<result>24_005_991</result>