Calculate the value of 17*18+18*19+19*20+...+29*30.
计算17*18+18*19+19*20+…+29*30的值．
<gadget id="calculator">29 * 30 * 31</gadget>
<output>26_970</output>

<gadget id="calculator">16 * 17 * 18</gadget>
<output>4_896</output>

<gadget id="calculator">26_970 - 4_896</gadget>
<output>22_074</output>

<gadget id="calculator">22_074 / 3</gadget>
<output>7_358</output>

<result>7_358</result>