A publishing house compiles a book with 1024 pages, how many digits are used just to code the pages?
某出版社编一本1024页的数，仅编页码就的用去多少个数码？
<gadget id="calculator">90 * 2</gadget>
<output>180</output>

<gadget id="calculator">999 - 100</gadget>
<output>899</output>

<gadget id="calculator">899 + 1</gadget>
<output>900</output>

<gadget id="calculator">900 * 3</gadget>
<output>2_700</output>

<gadget id="calculator">1_024 - 1_000</gadget>
<output>24</output>

<gadget id="calculator">24 + 1</gadget>
<output>25</output>

<gadget id="calculator">25 * 4</gadget>
<output>100</output>

<gadget id="calculator">9 + 180 + 2_700 + 100</gadget>
<output>2_989</output>

<result>2_989</result>