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 Q]: WnEarWPNhRyvtQbwSubBUVr
[EX A]: WnEarPNhRyvtQbwSuBUV

[EX Q]: MVSgVVGyEUoNRFFkrTkrgLcYYSPPAX
[EX A]: MVSgGyEUoNRFkrTLcYPAX

[EX Q]: ZpBNToFTMLvOZFoGObBhCXaGqCf
[EX A]:
ZpBNToFMLvOGbhCXaqf