You are given a code:

def main_solution(x):
    return ('drfm' + 'bmmdro')

Can you predict the output of `main_solution("drkxr")` 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": "drkxr"}, "ref_output": "drfmbmmdro", "ref_code": "def main_solution(x):\n    return ('drfm' + 'bmmdro')", "funcname": "main_solution"}
rule