If the sequence: 1, 2, 3, 4, 5, ... n, there are 99 multiples of 3 and 7. Then, what is the maximum n.
若数列：1、2、3、4、5、…n中，3和7的倍数共有99个．那么，n最大是多少．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 / 7</gadget>
<output>1/7 = around 0.142857</output>

<gadget id="calculator">1 / 21</gadget>
<output>1/21 = around 0.047619</output>

<gadget id="calculator">(1/7) - (1/21)</gadget>
<output>2/21 = around 0.095238</output>

<gadget id="calculator">(1/3) + (2/21)</gadget>
<output>3/7 = around 0.428571</output>

<gadget id="calculator">99 / (3/7)</gadget>
<output>231</output>

<gadget id="calculator">231 + 2</gadget>
<output>233</output>

<result>233</result>