On Sep 19th, you sold short 5,200 shares of stock A at $156 per share. Your initial margin requirement is 50 percent. Assuming there was no commission and interest fees and no dividends. After two weeks, Stock A's price went up to $190 per share, and you received a margin call from the broker. If you close your position what would be your return? How much additional cash must be put in to maintain the margin at 40 percent?