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]: FGhwvvBGIRusWiqUytlwJNHjLDB
[EX A]: FGhwvBIRusWiqUytlJNHjLD

[EX Q]: IpFBHqaAeWEXwHnzkFhZQTlS
[EX A]: IpFBHqaAeWEXwnzkhZQTlS

[EX Q]: cVdvXEQiSKllmgVBHwPRZPNMQfiQe
[EX A]:
cVdvXEQiSKlmgBHwPRZNMfe