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.
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Question: PHgBWkqIkZcjMbMhNzGqExRfuK

Answer: PHgBWkqIZcjMbhNzGExRfuK


Question: CHIKoErswWcbipbgjjmyU

Answer: CHIKoErswWcbipgjmyU


Question: nXnGFzHFYudOiHyWLZXQfpw

Answer:
nXGFzHYudOiyWLZQfpw