□/20=16…□, when the remainder is the largest, what is the dividend.
□/20=16…□，当余数最大时，被除数是多少．
<gadget id="calculator">20 * 16</gadget>
<output>320</output>

<gadget id="calculator">20 - 1</gadget>
<output>19</output>

<gadget id="calculator">320 + 19</gadget>
<output>339</output>

<result>339</result>