manuscript has 4 pages, 39 lines per page, and 25 characters per line. How many characters are there in this manuscript?
一份稿件共有4页，每页39行，每行25个字，这份稿件共有多少个字．
<gadget id="calculator">25 * 39 * 4</gadget>
<output>3_900</output>

<result>3_900</result>