Convert a natural number into base 5 to get a three-digit number A, and then convert this natural number into base 6 to get a three-digit number B. It is found that the two three-digit numbers of A and B are mutually inverse ordinal numbers. Find this Natural number?
把一个自然数化成5进制，得到一个三位数A，再把这个自然数化成6进制，得到一个三位数B，发现A的和B这两个三位数是互为反序数，求这个自然数？
<gadget id="calculator">25 * 3</gadget>
<output>75</output>

<gadget id="calculator">5 * 2</gadget>
<output>10</output>

<gadget id="calculator">75 + 10 + 2</gadget>
<output>87</output>

<result>87</result>