You are given a code:

def main_solution(x):
    return ('ukeopl' + 'excm')

Can you predict the output of `main_solution("efyexa")` 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": "efyexa"}, "ref_output": "ukeoplexcm", "ref_code": "def main_solution(x):\n    return ('ukeopl' + 'excm')", "funcname": "main_solution"}
rule