A stock price is $100 now. In 1 month it can go 5% up or down. In the second month it can go 5%up or down. In the third month it can go 5% up or down. Construct a binomial tree for this stock. The annual interest rate is 10% with continuous compounding. Use risk neutral probabilities to calculate the value of a three-month European put with the strike price 102. Calculate the put value at each node of the tree. Aso calculate that of American put with strike price 102 and everything else the same (and when you should exercise early the put)