For the inventory and workforce planning problem, confirm that the optimal plan using a level strategy that minimizes the number of new hires and layoffs without using any overtime has a minimum cost of $2,332,500, with 5 new hires at the very beginning and a remaining safety inventory of 50 items at the end (hint: you may use the Solver or just insert the solution that was shown in class). How many additional hires (in addition to the 5) are required at the beginning if this safety inventor shall be increased to at least 500 items at the end of the year?