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: QyYdHTVupfGnwJLOYhBhifYIjPSd

SOLUTION: QyYdHTVupfGnwJLOhBiIjPS

PROBLEM: QuMNYgXJKXvbSqRhUHAfsIAxqUYb

SOLUTION: QuMNYgXJKvbSqRhUHAfsIx

PROBLEM: uWQyOyRMKvmSdratHfTdq

SOLUTION:
uWQyORMKvmSdratHfTq