1998*19991999-1999*19981998.
1998*19991999-1999*19981998．
<gadget id="calculator">1_998 * 19_991_999</gadget>
<output>39_944_014_002</output>

<gadget id="calculator">1_999 * 19_981_998</gadget>
<output>39_944_014_002</output>

<gadget id="calculator">39_944_014_002 - 39_944_014_002</gadget>
<output>0</output>

<result>0</result>