public class RetirementAccount
{
    private double     deposit, rate;
    
    /**
     * Explicit Value Constructor
     *
     * @param deposit   The deposit made (at the beginning of) each year
     * @param rate      The interest rate (which is guaranteed)
     */
    public RetirementAccount(double deposit, double rate)
    {
       this.deposit = deposit;
       this.rate    = rate;
    }
    

    /**
     * Calculates the value of this RetirementAccount in 
     * a given number of years
     *
     * @param years   The number of years
     */
    public double valueIn(int years)
    {
    }
}