Trailing Zeroes in N!

using System;

class TrailingZeroesInNFactorial
{
    static void Main()
    {
        int n = int.Parse(Console.ReadLine());
        int countZero = 0;

        for (int i = 1; i <= n; i++)
        {
            if (i % 5 == 0)
            {
                if (i % 10 == 0)
                {
                    countZero += GetZero(i);
                }
                else
                {
                    countZero++;
                }
            }
        }

        Console.WriteLine(countZero);
    }

    static int GetZero(int number)
    {
        int count = 0;
        while (number % 10 == 0)
        {
            number = number / 10;
            count++;
        }
        return count++;
    }
}