Problem Statement

Description: You're handed a string of characters. Your task is to strip out any characters that sit directly next to a repeat of themselves, so that only unique characters remain in sequence. Input Format: A single line containing the string S. Constraints: The string S consists of only lowercase English alphabets. The length of S is at most 10 5 . Examples: Example 1: Input: abbcccdd Output: abcd Explanation: Here, "bb", "ccc", and "dd" are runs of the same character sitting back to back. Collapsing each of those runs down leaves the string "abcd".