/**
 * 1332. Remove Palindromic Subsequences
 * You are 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. Note that a subsequence does not necessarily need to be contiguous.
 *
 * A string is called palindrome if is one that reads the same backward as well as forward.
 *
 * Refer: 220122-CN.cpp
 */