667*668*669-666*668*670=how many.
667*668*669-666*668*670=多少．
<gadget id="calculator">667 * 668 * 669</gadget>
<output>298_076_964</output>

<gadget id="calculator">666 * 668 * 670</gadget>
<output>298_074_960</output>

<gadget id="calculator">298_076_964 - 298_074_960</gadget>
<output>2_004</output>

<result>2_004</result>