You are given a code:

def main_solution(x):
    return (func_15(x) + ('ber').upper())

Can you predict the output of `main_solution("idyhvkvgc")` without writing any code? Please reason and put your final answer in the following json format: {"output": <your output>}, where <your output> should be the final string.
user
{"ref_input": {"x": "idyhvkvgc"}, "ref_output": "\u00abi\u00bb\u00abd\u00bb\u00aby\u00bb\u00abh\u00bb\u00abv\u00bb\u00abk\u00bb\u00abv\u00bb\u00abg\u00bb\u00abc\u00bbBER", "ref_code": "def main_solution(x):\n    return (func_15(x) + ('ber').upper())", "funcname": "main_solution"}
rule