class Program:
    def __init__(self) -> None:
        self.count_of_numbers = 0
        self.numbers = list[int]()
        self.result = 0
    
    def get_number(self, value_name: str) -> int:
        print(f"Enter the {value_name}:\t", end="")
        value_name = value_name[0].upper() + value_name[1:]
        while True:
            try:
                return int(input())
            except ValueError:
                print(f"{value_name} must be 10-based number! Try again: ", end="")

    def get_count_of_numbers(self) -> None:
        self.count_of_numbers = self.get_number("count of numbers")
    
    def get_numbers(self) -> None:
        while len(self.numbers) < self.count_of_numbers:
            self.numbers.append(self.get_number("number"))
    
    def filter_numbers(self) -> None:
        self.numbers = list(filter(lambda x: not x%9, self.numbers))
        self.numbers = list(filter(lambda x: str(x)[-1] == "6", self.numbers))
    
    def calculate_result(self) -> None:
        if len(self.numbers) == 0:
            self.result = 0
        else:
            self.result = max(self.numbers) - min(self.numbers)
    
    def print_result(self) -> None:
        print(self.result)
    
    def run(self) -> None:
        self.get_count_of_numbers()
        self.get_numbers()
        self.filter_numbers()
        self.calculate_result()
        self.print_result()


if __name__ == "__main__":
    program = Program()
    program.run()