No Palindromes

Alice has a string $S$ of length $N$, consisting of lowercase English letters. She wants to remove a lexicographically minimal subsequence$^{\dagger}$ $T$ from $S$ such that after removing $T$, the remaining characters of $S$ cannot be rearranged to form a [palindrome](https://en.wikipedia.org/wiki/Palindrome#Characters,_words,_or_lines). Your task is to help Alice by printing the subsequence $T$