Russ Tickman is a dairy farmer. He consumes milk and other goods. His utility function is given by U(x, y) = y(x + 1), where x is his milk consumption and y is his consumption of other goods. His initial endowment is 19 units of milk per day and no units of other goods. If the price of milk is 2 and the price of other goods is 1, how much milk does he consume?