You are given a code:

def main_solution(x):
    return func_3('sqrc')

Can you predict the output of `main_solution("butm")` 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": "butm"}, "ref_output": "cqrs", "ref_code": "def main_solution(x):\n    return func_3('sqrc')", "funcname": "main_solution"}
rule