There are two gates with coded locks. Password prompt for the first door. Choose two different numbers from 0 to 9 to form the largest number and the smallest number, and then subtract them. At this rate, you will find the password of the first door. 8 1- 18 equals 63, 63-36 equals 27, 72-27 equals 45 ... The password prompt of the second door, select three different numbers from 0 to 9, and subtract them to form the largest number and the smallest number. If you do this, you will find the password for the second door. 972-279 equals 693, 963-369 equals 594, ... Find the password.