gistfile1.cs

using System;
using System.Numerics; // Add a reference to System.Numerics.dll
using System.Runtime.CompilerServices;
using System.Threading;

class Program
{
    static void Main()
    {
        Console.WriteLine(Factorial(15000));
    }

    static BigInteger Factorial(BigInteger n)
    {
        BigInteger? result = null;
        int stackSize = 0x40000;
        
        while (true)
        {
            var worker = new Thread(
                () => { try { result = FactorialRecursive(n); } catch (InsufficientExecutionStackException) { } },
                stackSize);

            worker.Start();
            worker.Join();

            if (result.HasValue)
            {
                return result.Value;
            }

            stackSize *= 2;
        }
    }

    static BigInteger FactorialRecursive(BigInteger n)
    {
        RuntimeHelpers.EnsureSufficientExecutionStack();
        return n == 0 ? 1 : n * FactorialRecursive(n - 1);
    }
}