You are given a code:

def main_solution(x):
    return func_15(('jtncq').upper())

Can you predict the output of `main_solution("rzgclkijyp")` 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": "rzgclkijyp"}, "ref_output": "\u00abJ\u00bb\u00abT\u00bb\u00abN\u00bb\u00abC\u00bb\u00abQ\u00bb", "ref_code": "def main_solution(x):\n    return func_15(('jtncq').upper())", "funcname": "main_solution"}
rule