Find the law and fill in the numbers: 1, 4, 7, 10, ... how much (fill in the 100th number)
找规律填数：1，4，7，10，…多少(填第100个数)
<gadget id="calculator">3 * 100</gadget>
<output>300</output>

<gadget id="calculator">300 - 2</gadget>
<output>298</output>

<result>298</result>