Calculation: 2000*1999-1999*1998+1998*1997-1997*1996+1996*1995-1995*1994.
计算：2000*1999-1999*1998+1998*1997-1997*1996+1996*1995-1995*1994．
<gadget id="calculator">2_000 * 1_999</gadget>
<output>3_998_000</output>

<gadget id="calculator">1_999 * 1_998</gadget>
<output>3_994_002</output>

<gadget id="calculator">3_998_000 - 3_994_002</gadget>
<output>3_998</output>

<gadget id="calculator">1_998 * 1_997</gadget>
<output>3_990_006</output>

<gadget id="calculator">1_997 * 1_996</gadget>
<output>3_986_012</output>

<gadget id="calculator">3_990_006 - 3_986_012</gadget>
<output>3_994</output>

<gadget id="calculator">1_996 * 1_995</gadget>
<output>3_982_020</output>

<gadget id="calculator">1_995 * 1_994</gadget>
<output>3_978_030</output>

<gadget id="calculator">3_982_020 - 3_978_030</gadget>
<output>3_990</output>

<gadget id="calculator">3_998 + 3_994 + 3_990</gadget>
<output>11_982</output>

<result>11_982</result>