A book has a total of 200 pages. When typesetting, one lead type can only place one number. How many typefaces should be used to arrange the page numbers of this book?
一本书共200页，排版时一个铅字只能排一位数字，那么排这本书的页码共要用多少个铅字？
<gadget id="calculator">90 * 2</gadget>
<output>180</output>

<gadget id="calculator">101 * 3</gadget>
<output>303</output>

<gadget id="calculator">9 + 180 + 303</gadget>
<output>492</output>

<result>492</result>