For a three-digit number, the number on each digit is one of 0, 7, and 9, and the two adjacent numbers are different, then how many three-digit numbers satisfy the condition?
一个三位数，每一位数上的数字都是0、7、9中的某一个，并且相邻的两个数字不相同，那么共有多少个满足条件的三位数．
<gadget id="calculator">2 * 2 * 2</gadget>
<output>8</output>

<result>8</result>