You are given a code:

def main_solution(x):
    return (func_13('krye', '_') + ('smplmq' + 'fbpfus'))

Can you predict the output of `main_solution("kcrzfsfqt")` 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": "kcrzfsfqt"}, "ref_output": "k_r_y_esmplmqfbpfus", "ref_code": "def main_solution(x):\n    return (func_13('krye', '_') + ('smplmq' + 'fbpfus'))", "funcname": "main_solution"}
rule