Problem 6. Calculate N! / K!

using System;

    class CalculateFakturiel
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Enter N=");
            int N = int.Parse(Console.ReadLine());
            Console.WriteLine("Enter K=");
            int K = int.Parse(Console.ReadLine());
            int sumK=1;
            int sumN = 1;
            for (int i = 1; i <= N; i++ )
            {
                sumN *= i;
            }
            for (int i = 1; i <= K; i++)
            {
                sumK *= i;
            }
            int sumF = sumN / sumK;
            Console.WriteLine(sumF);
        }
    }