public class Nim {

    public static boolean isValidEntry(int amountOfStones, int userInput) {
        return userInput <= 3 && amountOfStones <= amountOfStones;
    }

    public static int drawStones() {
        int computerMove = (int) (3 * Math.random() + 1);
        return computerMove;
    }

    public static int humansTurn(int amountOfStones, Scanner input) {
        int userInput;

        do {
            System.out.print("\tThere are " + amountOfStones + " Stones. How many would you like?: ");
            userInput = Integer.parseInt(input.nextLine());
        } while (!isValidEntry(amountOfStones, userInput) && userInput != 0);
        amountOfStones -= userInput;
        System.out.println("\tThere are " + amountOfStones + " Stones Left.");

        if (amountOfStones == 1) {
            System.out.println("\tYou Win!");
        }
        return amountOfStones;
        }






    public static int computersTurn(int amountOfStones) {
        int newDraw = drawStones();
        int newDraw1 = drawStones();
        if (isValidEntry(amountOfStones, newDraw)) {
            System.out.println("\tThe computer takes " + newDraw + " Stones.");
            amountOfStones -= newDraw;
            System.out.println("\tThere are now " + +amountOfStones + " Stones.");
        } while (!isValidEntry(amountOfStones, newDraw));

        if (amountOfStones == 1) {
            System.out.println("\tComputer wins!");

            } else {

                 newDraw1 = drawStones();
            } while (newDraw1 <= 3 && newDraw1 > amountOfStones) {

            }



        return amountOfStones;
    }












    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int bothTurns = (int) (16 * Math.random() + 15);
        do {
        bothTurns = humansTurn(bothTurns, input);
        bothTurns = computersTurn(bothTurns);
    } while (bothTurns != 0);
    }
}