□/28=19…▲, □What is the maximum.
□/28=19…▲，□最大是多少．
<gadget id="calculator">19 * 28</gadget>
<output>532</output>

<gadget id="calculator">28 - 1</gadget>
<output>27</output>

<gadget id="calculator">532 + 27</gadget>
<output>559</output>

<result>559</result>