Calculation: 1+3+5+...+2015+2017+2015+2013+...+5+3+1.
计算：1+3+5+…+2015+2017+2015+2013+…+5+3+1．
<gadget id="calculator">1 + 2_017</gadget>
<output>2_018</output>

<gadget id="calculator">1_009 / 2</gadget>
<output>1_009/2 = around 504.5</output>

<gadget id="calculator">2_018 * (1_009/2)</gadget>
<output>1_018_081</output>

<gadget id="calculator">1 + 2_015</gadget>
<output>2_016</output>

<gadget id="calculator">1_008 / 2</gadget>
<output>504</output>

<gadget id="calculator">2_016 * 504</gadget>
<output>1_016_064</output>

<gadget id="calculator">1_018_081 + 1_016_064</gadget>
<output>2_034_145</output>

<result>2_034_145</result>