1991*199219921992-1992*199119911991.
1991*199219921992-1992*199119911991．
<gadget id="calculator">1_991 * 199_219_921_992</gadget>
<output>396_646_864_686_072</output>

<gadget id="calculator">1_992 * 199_119_911_991</gadget>
<output>396_646_864_686_072</output>

<gadget id="calculator">396_646_864_686_072 - 396_646_864_686_072</gadget>
<output>0</output>

<result>0</result>