2008+2007-2006-2005+2004+2003-2002-2001+...+4+3-2-1.
2008+2007-2006-2005+2004+2003-2002-2001+…+4+3-2-1．
<gadget id="calculator">3 - 2 - 1</gadget>
<output>0</output>

<gadget id="calculator">4 + 0 + 0</gadget>
<output>4</output>

<gadget id="calculator">4 * 502</gadget>
<output>2_008</output>

<result>2_008</result>