You are given a code:

def main_solution(x):
    return func_20(func_13('iosmr', '_'), func_15('pqcba'))

Can you predict the output of `main_solution("uigttb")` 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": "uigttb"}, "ref_output": "i\u00ab_po\u00bb_\u00absq_\u00bbm\u00ab_cr\u00bb\u00abb\u00bb\u00aba\u00bb", "ref_code": "def main_solution(x):\n    return func_20(func_13('iosmr', '_'), func_15('pqcba'))", "funcname": "main_solution"}
rule