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.

[Q]: xpgVQicCOzavYkEiLbejlmU
[A]: xpgVQicCOzavYkELbejlmU


[Q]: OOwybftCNaoQnrkYlqucDuGvBwiB
[A]: OwybftCNaoQnrkYlqucDGvBi


[Q]: illrFjErfSgrAAErfKMlvbI
[A]:
ilrFjEfSgAKMvbI