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.

Ex Input:
YqrgFKzesbCXcEVMhcxZwdanPFR

Ex Output:
YqrgFKzesbCXcEVMhxZwdanPR


Ex Input:
NOXIdIppfrgUFWCgdPvNqsZOjPxB

Ex Output:
NOXIdpfrgUFWCPvqsZjxB


Ex Input:
iBHUXTOSUDFDFYvNfOBkPCAlvr

Ex Output:

iBHUXTOSDFYvNfkPCAlr