Finding Factorial of a Number using Function Delegates in C#

using System;
using System.Collections.Generic;

namespace AbundantCodeConsoleApp
{
    internal class Program
    {
        private delegate void result();

        private static void Main(string[] args)
        {
            System.Func<long, long> Fact =
            delegate(long Input)
            {
                if (Input == 1) return 1;
                long Output = 1;
                for (int indexer = 2; indexer <= Input; indexer++)
                    Output *= indexer;
                return Output;
            };
            Console.WriteLine(Fact(4));
            Console.ReadLine();
        }
    }
}