Program To Calculate Factorial of a Number in C#

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace ConsoleApplication1
{

    class CalcAvgPerc
    {

        static void Main(string[] args)
        {

            int i, fact = 1, n;

            Console.WriteLine("Enter the number to calculate factorial...");

            n = int.Parse(Console.ReadLine());

            Console.WriteLine("Calculating...");

            System.Threading.Thread.Sleep(1000);

            for (i = 1; i <= n; i++)

                fact = fact * i;

            Console.WriteLine("Factorial for number {0} is {1}", n, fact);

            Console.ReadKey();

        }

    }

}