Maximize palindromic strings after character swaps

You are given an integer n and an array of n lowercase strings `arr`. Operation (can be performed any number of times): choose two different strings `arr[i]` and `arr[j]`, pick one character from each string, and swap those two characters. After performing any sequence of such swaps, return the **maximum possible number of strings in `arr` that are palindromes**. Notes: - You may swap characters between any pair of strings, and you may repeat operations indefinitely. - Each string’s **length must remain the same**. Example: - Input: `arr = ["pass", "sas", "asps", "df"]` - Output: `3` (it is possible to make 3 of the strings palindromes).