20072008*20082007-20072007*20082008=how many.
20072008*20082007-20072007*20082008=多少．
<gadget id="calculator">20_072_007 * 20_082_007</gadget>
<output>403_086_185_078_049</output>

<gadget id="calculator">20_082_007 - 403_086_185_078_049 - 20_072_007</gadget>
<output>-403_086_185_068_049</output>

<gadget id="calculator">403_086_185_078_049 + (-403_086_185_068_049)</gadget>
<output>10_000</output>

<result>10_000</result>