A password box, its password is composed of 3 numbers between 0-9, (used numbers are not reused), how many times do you have to try at most? (the first digit of the password can be 0)
一个密码箱，它的密码是由0-9之间的3个数字组成，(用过的数字不重复使用)则至多要试多少次？(密码的第一个数字可以是0)
<gadget id="calculator">10 - 1</gadget>
<output>9</output>

<gadget id="calculator">10 - 1 - 1</gadget>
<output>8</output>

<gadget id="calculator">10 * 9 * 8</gadget>
<output>720</output>

<result>720</result>