In a certain game, a coin is flipped 4 times. If exactly one head comes up then the player gets a $1 profit ($1 more than the cost of the ticket). If exactly 2 heads come up then the player gets a $2 profit. If exactly 3 heads come up then the player gets a $4 profit. If all 4 are heads then the player gets an $8 profit. If no heads come up then he or she loses the cost P of the ticket. What should the cost P of the ticket be to make it a fair game? The cost should be $. (-24), 24, 40, or (-40)