How can I find the Bayesian Nash equilibrium of this game?

Consider the following two-player team production problem. The players simultaneously choose effort levels (so for player 1' ), and revenue is given by 2k(a1 + (:2). Suppose that player i's cost of effort is (11-2. Revenue is split equally between the players, so player i's payoff is Mal + a2) of . Assume that the value of k is privately observed by player 1 prior to her selection of :11. Player 2 does not know the value of 1: before choosing 512. Player 2 knows only that k is either 2 or 4 (low or high), each with probability g