// A subclass of the savings account class.
// This example illustrates adding instance variables and
// overriding a method in the parent class.


public class AccountCmp extends Account
{ 
  // instance variables 
  //  also inherits name, balance, interestrate
  static double minbalance = 6000.;
  static double penalty = 20.;

  // constructor method is same as parent
  public AccountCmp (String n, double b)
  { super (n, b);  }

  // override one method
  //  also inherits getname, getbalance, withdraw, and deposit
  public double monthactivity()
  { if (balance < minbalance) balance -= penalty;
    double newbalance = balance * 
                     (double)(Math.pow (1 + (interestrate/12)/30, 30));
    double interest = newbalance - balance;
    balance = newbalance;
    return interest;
  }
}