TrailingZeroesInN

using System;

//Write a program that calculates with how many zeroes the factorial of a given number n has at its end.
// Your program should work well for very big numbers, e.g. n=100000

    class TrailingZeroesInN
    {
        static void Main()
        {
            BigInteger n = BigInteger.Parse(Console.ReadLine());
            BigInteger nFaktorial = 1;


            for (int i = 1; i <= n; i++)
            {
                nFaktorial *= i;
            }
            Console.WriteLine(nFaktorial);
            int count = 0;
            while (nFaktorial % 10 == 0)
            {
                count++;
                nFaktorial = nFaktorial / 10;
            }
            Console.WriteLine("Zeros = " + count);
        }
    }