Calculation: ((1/2)+(1/3)+…+(1/2005))(1+(1/2)+(1/3)+…+(1/2004))-(1+ (1/2)+(1/3)+...+(1/2005))((1/2)+(1/3)+...+(1/2004)).
计算：((1/2)+(1/3)+…+(1/2005))(1+(1/2)+(1/3)+…+(1/2004))-(1+(1/2)+(1/3)+…+(1/2005))((1/2)+(1/3)+…+(1/2004))．
<gadget id="calculator">1 / 2_005</gadget>
<output>1/2_005 = around 0.000499</output>

<result>1/2_005 = around 0.000499</result>