You are given a code:

def main_solution(x):
    return ('upd' + 'wqs')

Can you predict the output of `main_solution("nqqhiv")` 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": "nqqhiv"}, "ref_output": "updwqs", "ref_code": "def main_solution(x):\n    return ('upd' + 'wqs')", "funcname": "main_solution"}
rule