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]: ptUIcSNsiRtUWfLGkAOAf
[EX A]: ptUIcSNsiRWfLGkAO

[EX Q]: DmWHbaDBQZdQpXVeMeiml
[EX A]: DmWHbaBQZdpXVeMil

[EX Q]: NmtgUlgBDHQDBjDaXxen
[EX A]:
NmtgUlBDHQjaXxen