A company has assigned a distinct 3-digit code number to each of its 330 employees. Each code number was formed from the digits
$$2, 3, 4, 5, 6, 7, 8, 9$$
and no digit appears more than once in any one code number. How many unassigned code numbers are there?
6
58
174
182
399
总可能数减去330=剩下的
8*7*6—330