Consider stock S, which is traded at the price of $50, and has a return volatility of 68% pa. The riskfroe rate of interest is 5.5% po. You are shorting an 8-month put option on the stock with exercise price of $43. How many shares do you need to hedge this short put? Write the answer in number, round it to 4 decimal places. Use plus/minus sign to indicate long/short position. For example, if you need to long 5 shares, write "5.0000", if you need to short 5 shares, write -5.0000