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.

Input: Consider Input: HaddRfDDTMuuYNqxfFpkUUxgu

Output: HadRfDTMuYNqxFpkUg

Input: Consider Input: ymiDSDINLYJcPFTeXDVvWdA

Output: ymiDSINLYJcPFTeXVvWdA

Input: Consider Input: syWqVWrvlDarbXGGXvjghpC
Output: syWqVrvlDabXGjghpC