Mr$.$ X plans to retire at age $63,$ and he believes that he can live comfortably with an annual pension of $$89,000,$ to be withdrawn at the begninning of each year in his retirement. Suppose his pension account will generate $9\mathrm{.}3\%$ of annual interest rate, and suppose Mr$.$ X believes that he will live to $104.$ In order to have sufficient money for his retirement, what is the minimum amount that Mr$.$ X must have saved up in his pension account at the time of his retirement at age $63?$