The page number of a book uses 2691 digits in typesetting, how many pages does the book have in total?
一本书的页码，在排版时用了2691个数码，则这本书一共有多少页？
<gadget id="calculator">2 * 90</gadget>
<output>180</output>

<gadget id="calculator">2_691 - 9 - 180</gadget>
<output>2_502</output>

<gadget id="calculator">2_502 / 3</gadget>
<output>834</output>

<gadget id="calculator">834 + 90 + 9</gadget>
<output>933</output>

<result>933</result>