Calculation: (1+3+5+...+2015)-(2+4+6+...+2014).
计算：(1+3+5+…+2015)-(2+4+6+…+2014)．
<gadget id="calculator">1 + 2_015</gadget>
<output>2_016</output>

<gadget id="calculator">2_016 / 2</gadget>
<output>1_008</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">2 + 2_014</gadget>
<output>2_016</output>

<gadget id="calculator">2_014 / 2</gadget>
<output>1_007</output>

<gadget id="calculator">1_007 / 2</gadget>
<output>1_007/2 = around 503.5</output>

<gadget id="calculator">2_016 * (1_007/2)</gadget>
<output>1_015_056</output>

<gadget id="calculator">1_016_064 - 1_015_056</gadget>
<output>1_008</output>

<result>1_008</result>