two-digit number, write 5 in front of it, the three-digit number formed is 18 times less than the original two-digit number, what is the original two-digit number?
一个两位数，在它的前面写上5，所成的三位数比原两位数的8倍少18，原来的两位数是多少？
<gadget id="calculator">18 + 500</gadget>
<output>518</output>

<gadget id="calculator">8 - 1</gadget>
<output>7</output>

<gadget id="calculator">518 / 7</gadget>
<output>74</output>

<result>74</result>