Louise wants to retire in 20 years with enough savings in her RRSP to be able to purchase a 25-year annuity that will pay her $4000 at the end of every month. She has already accumulated $50,000 in her RRSP. In order to meet her goal, what RRSP contribution should Louise make at the end of each of the next 20 years? Assume she earns 4% compounded annually on her RRSP, and 3.6% compounded monthly on the annuity purchased with her RRSP funds.