Legend has it that there are 7 different dragon balls on the earth. If you find all 7 dragon balls and line them up in a specific order, a dragon will appear. The evil Cell found the 7 Dragon Balls, but he didn't know the specific order to arrange them. I would like to ask: How many times will Cell, who is unlucky, have to try to meet Shenlong?
传说地球上有7颗不同的龙珠，如果找齐这7颗龙珠，并且按照特定顺序排成一行就会有神龙出现．邪恶的沙鲁找到了这7颗龙珠，但是他不知道排列的特定顺序．请问：运气不好的沙鲁最坏要试几次才能遇见神龙？
<gadget id="calculator">7 * 6 * 5 * 4 * 3 * 2 * 1</gadget>
<output>5_040</output>

<result>5_040</result>