Gordon Gecko is 25 years old today and is beginning to plan for his retirement. He wants to set aside equal amounts for the next 40 years so that he can retire at age 65. He expects to live to a maximum age of 90 and wants to be able to withdraw $50,000 per year for 25 years at the end of each year. The account is expected to earn 8% APR for the working period and 5% APR for the retirement period. How much must he invest at the end of each month to achieve this goal?