def is_magic_gon(numbers: list[int]) -> bool:
    if len(numbers) % 3 != 0:
        raise ValueError("a gon ring should have a length that is a multiple of 3")

    if min(numbers[::3]) != numbers[0]:
        return False

    total = sum(numbers[:3])

    return all(sum(numbers[i : i + 3]) == total for i in range(3, len(numbers), 3))