(-1)**2003+(-1)**2004=how much.
(-1)**2003+(-1)**2004=多少．
<gadget id="calculator">(-1) ** 2_003</gadget>
<output>-1</output>

<gadget id="calculator">(-1) ** 2_004</gadget>
<output>1</output>

<gadget id="calculator">(-1) + 1</gadget>
<output>0</output>

<result>0</result>