TASK DEFINITION: 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.
PROBLEM: PLLbnDcbUakITKnNmHkiB

SOLUTION: PLbnDcUakITKNmHiB

PROBLEM: IVaFaBpctNpNNKUdFNuXUAvfZNlVKL

SOLUTION: IVaFBpctNKUduXAvfZlL

PROBLEM: BeZEQbbgVZcjWBaojjCUQbZhonBH

SOLUTION:
BeZEQbgVcjWaoCUhnH