Kth Factorial

using System;
using System.Numerics;

namespace KthFactorial
{
    class RecursiveSolution
    {
        static void Main()
        {
            Console.Write("n = ");
            int n = int.Parse(Console.ReadLine());
            Console.Write("k = ");
            int k = int.Parse(Console.ReadLine());
            BigInteger result = CalculateKthFactorial(n, k);
            Console.WriteLine("The {0}-th factorial of {1} is {2}", k, n, result);
        }

        /// <summary>
        /// Finds the kth factorial of n.
        /// The idea is that kth factorial = n^k * (n-1)^k * (n-2)^k * ... * 1
        /// </summary>
        /// <returns>Recursive call or 1.</returns>
        private static BigInteger CalculateKthFactorial(int n, int k)
        {
            if (n <= 1)
            {
                return 1;
            }
            return RaiseToThePowerOf(n, k) * CalculateKthFactorial(n - 1, k);
        }

        /// <summary>
        /// Raise a to the power of b. Does the same as Math.Pow(a, b), but it's faster because b is integer.
        /// </summary>
        /// <returns>a^b</returns>
        private static BigInteger RaiseToThePowerOf(BigInteger a, int b)
        {
            BigInteger result = a;
            for (int i = 1; i < b; i++)
            {
                result *= a;
            }
            return result;
        }
    }
}