using System;

public class Program

{

    public static void Main()

    {

        customer cust = new customer();

        AmericanCustomer acust = new AmericanCustomer();

        Console.WriteLine(cust.dollarPrice());

        Console.WriteLine(acust.dollarPrice());

    }

}

​

public class customer

{

    public virtual decimal dollarPrice()

    {

        return 1.0M;

    }

}

​

public class AmericanCustomer:customer

{

    public  override decimal dollarPrice()

    {

        return 1.2M;

    }

}