Please calculate: 1+2+3+...+2006=how much.
请你计算：1+2+3+…+2006=多少．
<gadget id="calculator">1 + 2_006</gadget>
<output>2_007</output>

<gadget id="calculator">2_006 / 2</gadget>
<output>1_003</output>

<gadget id="calculator">2_007 * 1_003</gadget>
<output>2_013_021</output>

<result>2_013_021</result>