public class MathStuff {


    // Compute a^b

    public static int power (int a, int b)
    {
        if (b == 0) {
            return 1;
        }
        return (a * power (a, b-1));
    }
    

    // Compute n!

    static int factorial (int n)
    {
        if (n == 1) {
            return 1;
        }
        return ( n * factorial(n-1) );
    }


    // Compute f_n, the n-th Fibonacci number.

    static int fibonacci (int n)
    {
        // Base cases rolled into one:
        if (n <= 2) {
            return (n-1);
        }
        
        return ( fibonacci(n-1) + fibonacci(n-2) );
    }

}