You are given a code:

def main_solution(x):
    return ('cch' + 'kylgxp')

Can you predict the output of `main_solution("pntjvbiu")` 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": "pntjvbiu"}, "ref_output": "cchkylgxp", "ref_code": "def main_solution(x):\n    return ('cch' + 'kylgxp')", "funcname": "main_solution"}
rule