There are 5 seats open on the board of directors of Alpha, Inc. Jason wants to be positive that he can be elected to one of these positions. Alpha uses cumulative voting. There are 1,500 shares of Alpha stock outstanding. Twenty% of the shares are owned by Midge, 30% are owned by Peter, 10% are owned by Jeff, 25% are owned by Jason and the rest are owned by Edward. How many additional shares of stock must Jason buy to ensure that he wins a seat?