Factorial of a number

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;

namespace fact
{
    class Program
    {
        static void Main(string[] args)
        {
            int n, i, sum=1;
            Console.WriteLine("Enter The number");
            n = Convert.ToInt32(Console.ReadLine());
            Console.WriteLine("factorial of a number");
            for (i = 1; i <= n; i++)
            {
                sum = sum * i;
            }
            Console.WriteLine(sum);
            Console.ReadLine();
        }
    }
}