You are given a code:

def main_solution(x):
    return (func_20(x, 'fwm') + func_20('uye', 'wng'))

Can you predict the output of `main_solution("ltcaapdxu")` 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": "ltcaapdxu"}, "ref_output": "lftwcmaapdxuuwyneg", "ref_code": "def main_solution(x):\n    return (func_20(x, 'fwm') + func_20('uye', 'wng'))", "funcname": "main_solution"}
rule