Loops/Task 4 - Factorial divide

using System;
class FactorialDivision
{
    static void Main()
    {
        Console.WriteLine("Enter two numbers:");
        Console.Write("N!");
        int n = int.Parse(Console.ReadLine());
        Console.Write("K!");
        int k = int.Parse(Console.ReadLine());
        decimal factorialN = 1;
        decimal factorialK = 1;
        if ((n < 1) || (k < 1) || (n < k))
        {
            Console.WriteLine("You made wrong input!");
        }
        else
        {
            do
            {
                factorialN *= n;
                n--;
            }
            while (n > 0);
            do
            {
                factorialK *= k;
                k--;
            }
            while (k > 0);
            Console.WriteLine("N! / K! = {0}", factorialN / factorialK);
        }

    }
}