Uncle Fei, Xiaoyue, Dongdong, and Archie took the bus to the park together. After getting on the bus, they found 8 empty seats. How many different ways did they sit?
费叔叔、小悦、冬冬、阿奇四个人一块乘公共汽车去公园，上车后发现有8个空座位，他们一共有多少种不同的坐法？
<gadget id="calculator">8 * 7 * 6 * 5</gadget>
<output>1_680</output>

<result>1_680</result>