6. Player 1 and Player 2 are playing a game in which Player 1 has the first move at A in the decision tree shown below. Once Player 1 has chosen either Up or Down, Player 2, who can see what Player 1 has chosen, must choose Up or Down at B or C. Both players know the payoffs at the end of each branch.

Suppose Player 1 and Player 2 enter into a binding agreement in which Player 1 agrees to pay Player 2 a fixed amount of money to get Player 2 to play Up when it is Player 2's turn. How much will Player 1 have to pay Player 2 to get Player 2 to play Up? (10%)