String changeMiddle(String str): Returns a copy of the original string, but modified as follows: If the string has an odd number of characters, replace the middle letter with 3 capital A's. If the string has an even number of characters, replace the middle two letters with three capital Z's. The input string can be of any length, including 0. RUBRIC: It is not enough to just solve the problem. Make sure you use PROPER INDENTATION. You MUST use CURLY BRACKETS for all loops and if/else statements. Also, the more EFFICIENT your solution, the higher your grade. If you have extraneous (superfluous / unnecessary) code, deductions will be taken.