You are given a code:

def main_solution(x):
    return (func_5(x, 'vuy') + func_15('rowm'))

Can you predict the output of `main_solution("otyuvfblns")` 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": "otyuvfblns"}, "ref_output": "vuyotyuvfblns\u00abr\u00bb\u00abo\u00bb\u00abw\u00bb\u00abm\u00bb", "ref_code": "def main_solution(x):\n    return (func_5(x, 'vuy') + func_15('rowm'))", "funcname": "main_solution"}
rule