Minimum Operations to Make Character Frequencies Equal

Description

You are given a string s.

A string t is called good if all characters of t occur the same number of times.

You can perform the following operations any number of times:

- Delete a character from s.

- Insert a character in s.

- Change a character in s to its next letter in the alphabet.

Note that you cannot change 'z' to 'a' using the third operation.

Return the minimum number of operations required to make s good.