You are given a code:

def main_solution(x):
    return ('ytfr' + 'hapcz')

Can you predict the output of `main_solution("ntsj")` 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": "ntsj"}, "ref_output": "ytfrhapcz", "ref_code": "def main_solution(x):\n    return ('ytfr' + 'hapcz')", "funcname": "main_solution"}
rule