A firm and its union bargain as follows. First the union makes a wage demand, w. The

firm observes w and chooses whether or not to accept it. If the firm accepts, then it

chooses a level of employment, L. If it does not accept, then L is zero. The firm's payoff

is P = 6L^1/2 wL, and the union's payoff is u = (w B) L, where B > 0. (Assume that

if the firm is indifferent between accepting and not-accepting, it will choose to accept.)

Derive the unique subgame perfect equilibrium outcome.