A financial institution offers a derivative security called PutSQ with a payoff equal to max (580 - [S+], 0) at maturity, where S+ is the stock price at maturity in 1 year and [S+] is its square. Assume that the current stock price is $20 and that no dividend will be paid. The stock volatility is 30% and the risk-free interest rate is 2.40%. Use a 4-step binomial tree to compute the price of this derivative assuming it is American-style, i.e. it can be exercised at any time during its life. Show all details and explain clearly your steps. (6 marks)