Teacher Wang prints a 10-page review material, with 26 lines per page and 28 characters per line. How many characters are there in this review material?
王老师打印一份10页的复习资料，每页26行，每行28个字，这份复习资料有多少个字？
<gadget id="calculator">26 * 28 * 10</gadget>
<output>7_280</output>

<result>7_280</result>