Given a string s consisting only of letters 'a' and 'b'. In a single step you can remove one palindromic subsequence from s.
Return the minimum number of steps to make the given string empty.
A string is a subsequence of a given string, if it is generated by deleting some characters of a given string without changing its order.
A string is called palindrome if is one that reads the same backward as well as forward.
Example 1:
Input: s = "ababa"
Output: 1
Explanation: String is already palindrome
Example 2:
Input: s = "abb"
Output: 2
Remove palindromic subsequence "a" then "bb".
Link to challenge: https://leetcode.com/problems/remove-palindromic-subsequences/ or
https://leetcode.com/explore/challenge/card/march-leetcoding-challenge-2021/589/week-2-march-8th-march-14th/3665/
