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.
Example: abCCdDDgGGhi
Example solution: abCdDgGhi
Example explanation: The input string has 3 duplicate characters and the resulting output string has no duplicate characters.

Problem: QFAWjYIbRIJWvLvKLmdNsW

Solution: QFAWjYIbRJvLKmdNs