Given the natural number A/10=8...□, what is the largest natural number A?
已知自然数A/10=8…□，则自然数A最大为多少．
<gadget id="calculator">10 * 8</gadget>
<output>80</output>

<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">80 + 9</gadget>
<output>89</output>

<result>89</result>