sWAP cASE
Switch case of all letters in a string.
You are given a string and your task is to swap cases. In other words, convert all lowercase letters to uppercase letters and vice versa.
For Example:
Www.HackerRank.com → wWW.hACKERrANK.COM
Pythonist 2 → pYTHONIST 2
Input Format:
A single line containing a string S.
Constraints:
* 0