In order to number each page of a book one by one starting from 1, 666 numbers are used. How many pages does this book have.
为了给一本书的每一页从1开始逐页编上页码，共用了666个数字．这本书共有多少页．
<gadget id="calculator">2 * 90</gadget>
<output>180</output>

<gadget id="calculator">666 - 9 - 180</gadget>
<output>477</output>

<gadget id="calculator">477 / 3</gadget>
<output>159</output>

<gadget id="calculator">99 + 159</gadget>
<output>258</output>

<result>258</result>