If the six-digit number is 3ABABA is a multiple of 6, where A and B represent different numbers, how many such six-digit numbers are there?
若六位数是3ABABA是6的倍数，其中A、B表示不同的数字，则这样的六位数有多少个．
<gadget id="calculator">4 * 5</gadget>
<output>20</output>

<gadget id="calculator">20 - 2</gadget>
<output>18</output>

<result>18</result>