Implement `minimum_palindromic_block_changes(password, k)`. The password length is a multiple of `k`. Partition it into consecutive blocks of exactly `k` characters. You may replace any character with any lowercase English letter. Return the minimum number of replacements needed so that every block is a palindrome. ### Constraints - `1 <= len(password) <= 200000` - `1 <= k <= len(password)` and `len(password) % k == 0` - `password` contains only lowercase English letters. ### Examples - `"abcaabba"`, `k = 4` returns `1`: change the first block `abca` to a palindrome; `abba` already is one. - `"abcdef"`, `k = 3` returns `2`: each of `abc` and `def` needs one mirrored-pair change. - `"aaaa"`, `k = 1` returns `0`. ```hint Exercise both parity cases Test odd and even block lengths, including `k = 1` and an already-palindromic block. ``` ```hint Check edits at different locations Include blocks whose disagreements occur near the ends, near the center, and in more than one place. ```