Starting from 1, count every 3 numbers to get the sequence 1, 4, 7, 10, ..., and ask what is the 100th number.
自1开始，每隔3个数一数，得到数列1，4，7，10，…，问第100个数是多少．
<gadget id="calculator">100 - 1</gadget>
<output>99</output>

<gadget id="calculator">3 * 99</gadget>
<output>297</output>

<gadget id="calculator">1 + 297</gadget>
<output>298</output>

<result>298</result>