3. Andi and Brandon contribute to a public good they both enjoy. Let a denote a contribution by Andi, b a contribution by Brandon. Andi and Brandon may choose any nonnegative contribution levels. Suppose that the level of the public good is g determines the level of the public good. Andi and Brandon have the following payoffs: max{a, b}; that is, the maximum effort uA(g.a) = g -a up(g,b) = g -6. and They make their contributions simultaneously and independently. All the above is common knowledge. (a) Find all of the pure strategy Nash equilibria to this game. (b) Find a symmetric equilibrium to this game.