You are given a code:

def main_solution(x):
    return (('emyb' + x)).upper()

Can you predict the output of `main_solution("dhp")` 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": "dhp"}, "ref_output": "EMYBDHP", "ref_code": "def main_solution(x):\n    return (('emyb' + x)).upper()", "funcname": "main_solution"}
rule