You are given a code:

def main_solution(x):
    return (func_23('pvop', 2) + func_13(x, '_'))

Can you predict the output of `main_solution("rnxsusqc")` 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": "rnxsusqc"}, "ref_output": "pvop1r_n_x_s_u_s_q_c", "ref_code": "def main_solution(x):\n    return (func_23('pvop', 2) + func_13(x, '_'))", "funcname": "main_solution"}
rule