People A, B, C, and D are arranged to sit in a row of 8 seats. If any two people are not sitting next to each other, how many different ways of seating are there?
A、B、C、D四人被安排坐入排成一排的8个座位中，若任意两个人都不相邻而坐，共有多少种不同的入座方式．
<gadget id="calculator">4 * 3 * 2 * 1 * 5</gadget>
<output>120</output>

<result>120</result>