For a three-digit number, 3-9 is not used for the ones digit, 2-8 is not used for the tens digit, and 1-7 is not used for the hundreds digit. How many possibilities are there for this three-digit number?
一个三位数，个位上不用3～9，十位上不用2～8，百位上不用1～7，这个三位数一共有多少种可能？
<gadget id="calculator">2 * 3 * 3</gadget>
<output>18</output>

<result>18</result>