Factorial of a number in C#

using System;

using System.Collections.Generic;

using System.Linq;

using System.Text;

using System.Threading.Tasks;

namespace ConsoleApplication

{

    class Program

    {

        static void Main(string[] args)

        {

            int i, n, f;

            Console.WriteLine("enter the value of n");

            n = Convert.ToInt32(Console.ReadLine());

            f = n;

            for (i = n - 1; i >= 1; i--)

            {

                f = f * i;

            }

            Console.WriteLine("Factorial of given number is :" + f);

            Console.Read();

        }

    }

}