You are given a code:

def main_solution(x):
    return func_11(('ppf' + 'zbj'), 3)

Can you predict the output of `main_solution("ymmm")` 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": "ymmm"}, "ref_output": "ssicem", "ref_code": "def main_solution(x):\n    return func_11(('ppf' + 'zbj'), 3)", "funcname": "main_solution"}
rule