using System;

public enum AccountTransaction {Withdrawing, Depositing, Interests};

public class BankAccount {

   private double interestRate;
   private string owner;
   private decimal balance;

   public BankAccount(string owner): this(owner, 0.0) {
   }

   public BankAccount(string owner, double interestRate) {
     this.interestRate = interestRate;
     this.owner = owner; 
     this.balance = 0.0M;
   }   

   public decimal Balance () {
     return balance;
   }

   private void LogTransaction(AccountTransaction kind, DateTime dt, 
                               decimal amount){
     // It is an exercise to implement this method
   }

   public void Withdraw (decimal amount) {
     this.LogTransaction(AccountTransaction.Withdrawing,
                         DateTime.Now, amount);
     balance -= amount;
   }

   public void Deposit (decimal amount) {
     this.LogTransaction(AccountTransaction.Depositing, 
                         DateTime.Now, amount);
     balance += amount;
   }

   public void AddInterests() {
     decimal interests = balance * (decimal)interestRate;
     this.LogTransaction(AccountTransaction.Interests, 
                         DateTime.Now, interests);
     balance += interests;
   }    

   public override string ToString() {
     return owner + "'s account holds " +
           + balance + " kroner";
   }
}