You are given a code:

def main_solution(x):
    return func_20(func_13(x, '_'), func_15(x))

Can you predict the output of `main_solution("urgmyhepej")` 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": "urgmyhepej"}, "ref_output": "u\u00ab_ur\u00bb_\u00abgr_\u00bbm\u00ab_gy\u00bb_\u00abhm_\u00bbe\u00ab_yp\u00bb_\u00abeh_\u00bbj\u00abe\u00bb\u00abp\u00bb\u00abe\u00bb\u00abj\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_13(x, '_'), func_15(x))", "funcname": "main_solution"}
rule