using System;

public class Program

{

    public record Customer(int Age, bool IsVIP);

    public static void Main()

    {

        var customer1 = new Customer(Age: 65, IsVIP: false);

        var customer2 = new Customer(Age: 65, IsVIP: true);     

        var customer3 = new Customer(Age: 15, IsVIP: false);

        var customer4 = new Customer(Age: 30, IsVIP: true);

​

        Console.WriteLine(GetDiscount(customer1)); // Output: Senior discount

        Console.WriteLine(GetDiscount(customer2)); // Output: Senior VIP discount

        Console.WriteLine(GetDiscount(customer3)); // Output: Youth discount

        Console.WriteLine(GetDiscount(customer4)); // Output: VIP discount      

        //Console.WriteLine(GetDiscount(null));

    }

    public static string GetDiscount(Customer customer)

    {

        if (customer.Age < 18)

        {

            return "Youth discount";

        }

        else if (customer.Age >= 60 && customer.IsVIP)

        {

            return "Senior VIP discount";

        }

        else if (customer.Age >= 60)

        {

            return "Senior discount";

        }       

        else if (customer.IsVIP)

        {

            return "VIP discount";

        }

        else

        {

            return "No discount";

        }

    }

    public static string GetDiscountPattern(Customer customer) =>

    customer switch

    {

        { Age: < 18 } => "Youth discount",

        { Age: >= 60, IsVIP: true } => "Senior VIP discount",       

        { Age: >= 60 } => "Senior discount",

        { IsVIP: true } => "VIP discount",

        _ => "No discount"

    };  

}