You are given a code:

def main_solution(x):
    return func_20(('ncs' + 'nfzs'), func_4('twzgza'))

Can you predict the output of `main_solution("fks")` 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": "fks"}, "ref_output": "ntcwszngfzzas", "ref_code": "def main_solution(x):\n    return func_20(('ncs' + 'nfzs'), func_4('twzgza'))", "funcname": "main_solution"}
rule