You are given a code:

def main_solution(x):
    return ('qpe' + 'tzpir')

Can you predict the output of `main_solution("yvpbgrpnc")` 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": "yvpbgrpnc"}, "ref_output": "qpetzpir", "ref_code": "def main_solution(x):\n    return ('qpe' + 'tzpir')", "funcname": "main_solution"}
rule