In this task, you are given a string of characters. You need to remove duplicate characters from the string if any, and return the resulting string.

Example Input: nCTfNLTHhSZkAhJRYGwESheWQVNZQU
Example Output: nCTfNLHhSZkAJRYGwEeWQVU

Example Input: YqrgFKzesbCXcEVMhcxZwdanPFR
Example Output: YqrgFKzesbCXcEVMhxZwdanPR

Example Input: yNuwnqBsSCMSttcxfDtHV
Example Output:
yNuwnqBsSCMtcxfDHV