You are given a code:

def main_solution(x):
    return (func_13(x, '-') + func_15('ejvd'))

Can you predict the output of `main_solution("pphzvknoc")` 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": "pphzvknoc"}, "ref_output": "p-p-h-z-v-k-n-o-c\u00abe\u00bb\u00abj\u00bb\u00abv\u00bb\u00abd\u00bb", "ref_code": "def main_solution(x):\n    return (func_13(x, '-') + func_15('ejvd'))", "funcname": "main_solution"}
rule