You are given a code:

def main_solution(x):
    return func_5(('gzdu' + x), 'xkev')

Can you predict the output of `main_solution("fedbtfu")` 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": "fedbtfu"}, "ref_output": "xkevgzdufedbtfu", "ref_code": "def main_solution(x):\n    return func_5(('gzdu' + x), 'xkev')", "funcname": "main_solution"}
rule