You are given a code:

def main_solution(x):
    return func_20(func_13('jrchi', '_'), func_4('tvf'))

Can you predict the output of `main_solution("vaqlegkr")` 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": "vaqlegkr"}, "ref_output": "jt_vrf_c_h_i", "ref_code": "def main_solution(x):\n    return func_20(func_13('jrchi', '_'), func_4('tvf'))", "funcname": "main_solution"}
rule