You are given a code:

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

Can you predict the output of `main_solution("rytwewegc")` 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": "rytwewegc"}, "ref_output": "\u00abrr_\u00bby\u00ab_yt\u00bb_\u00abwt_\u00bbe\u00ab_ww\u00bb_\u00abee_\u00bbg\u00ab_wc\u00bb\u00abe\u00bb\u00abg\u00bb\u00abc\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_15(x), func_13(x, '_'))", "funcname": "main_solution"}
rule