Software developers at Amazon are developing a new library for Natural Language Processing. In one of its modules, every string needs to be preprocessed in a particular manner to find the length of its longest self-sufficient proper substring A self-sufficient proper substring is one where 1. the substring is not the entire string s 2.no letter that occurs inside the substring also occurs outside the substring Given the string fullString of length n, find the length of its longest self-sufficient proper substring. If none exists, return 0. Example fullString = "amazonservices" Here The length fullString, n = 14.