TASK DEFINITION: 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.
PROBLEM: FADtggVHWPgSKcVnyvGF

SOLUTION: FADtgVHWPSKcnyvG

PROBLEM: vpNNpsyAnsFJkHvrjgSkTOhHXIC

SOLUTION: vpNsyAnFJkHrjgSTOhXIC

PROBLEM: njmaCTiKTnSvvnwoINpZnCwuoerbw

SOLUTION:
njmaCTiKSvwoINpZuerb