Send messages, and don't worry about knowing how to access data - P1

DependOnBehaviourNotData-p1.md

    class Program
    {
        static void Main(string[] args)
        {
            Account freddie = new Account(5000000);

            // freddie buys a grand piano
            freddie.balance = freddie.balance - 500000m;

            // freddie buys a leather jacket
            freddie.balance = freddie.balance - 5000m;

            // freddie buys a beer in Singapore
            freddie.balance = freddie.balance - 20;            
        }                
    }


    public class Account
    {
        public decimal balance;

        public Account(decimal balance)
        {
            this.balance = balance;
        }
    }
    ```