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 Input:
upCjBxCmzQWZqyLQVAqDnEwMpIr

Ex Output:
upCjBxmzQWZqyLVADnEwMIr


Ex Input:
kjynMHqaVPzfJDTnXNHz

Ex Output:
kjynMHqaVPzfJDTXN


Ex Input:
gIbVlYsnmQJkeQqsrmuup

Ex Output:

gIbVlYsnmQJkeqrup