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]: XttLMRTVbiQDKPMEXyeXPSoDGCehY
[EX A]: XtLMRTVbiQDKPEyeSoGChY

[EX Q]: SFIxkcMKVMuCoybMuVPzYFOYUfd
[EX A]: SFIxkcMKVuCoybPzYOUfd

[EX Q]: gjroYPFlHUuyuFQeDOEpoLOWKZ
[EX A]:
gjroYPFlHUuyQeDOEpLWKZ

