Yost received $300$ NQOs $($each option gives Yost the right to purchase $10$ shares of Cutter Corporation stock for $$27$ per share$).$ At the time he started working for Cutter Corporation three years ago, Cutter's stock price was $$27$ per share. Yost exercised all of his options when the share price was $$54$ per share. Two years after acquiring the shares, he sold them at $$83$ per share.

Note: Input all amounts as positive values. Leave no answer blank. Enter zero if applicable.

c$.$ Assume that Yost is "cash poor" and needs to engage in a same$-$day sale in order to buy his shares. Due to his belief that the stock price is going to increase significantly, he wants to maintain as many shares as possible. How many shares must he sell in order to cover his purchase price and taxes payable on the exercise?