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]: ZpBNToFTMLvOZFoGObBhCXaGqCf
[EX A]: ZpBNToFMLvOGbhCXaqf

[EX Q]: FsDiXVqAymUcNSwuyNjb
[EX A]: FsDiXVqAymUcNSwujb

[EX Q]: AgGgzxvBjlCrysBmzQKfz
[EX A]:
AgGzxvBjlCrysmQKf