Can anyone help me?Bytelandian gold coins

Im using c#

using System;
using System.Threading;
using System.Runtime.InteropServices;

namespace codechef
{
class Program
{
    [DllImport("User32.Dll", EntryPoint = "PostMessageA")]
    private static extern bool PostMessage(IntPtr hWnd, uint msg, int wParam, int lParam);

    const int VK_RETURN = 0x0D;
    const int WM_KEYDOWN = 0x100;
    private decimal round(decimal i4, decimal i2, decimal i3)
    {
        return (Math.Round(i4,MidpointRounding.AwayFromZero) + Math.Round(i2,MidpointRounding.AwayFromZero) + Math.Round(i3, MidpointRounding.AwayFromZero));
    }
    static void Main(string[] args)
    {
        for(int ie=1;ie<=10;ie++)
        {
            string str = null;
            
            ThreadPool.QueueUserWorkItem((s) => 
            {
                Thread.Sleep(500);
                if(string.IsNullOrEmpty(str))
                {
                    var hWnd = System.Diagnostics.Process.GetCurrentProcess().MainWindowHandle;
                    PostMessage(hWnd, WM_KEYDOWN, VK_RETURN, 0);
                }
            });
            str = Console.ReadLine();
            if (string.IsNullOrEmpty(str))
            {
                break;
            }
            else
            {
                decimal i = decimal.Parse(str);
                decimal i2 = i / 2;
                decimal i3 = i / 3;
                decimal i4 = i / 4;
                if (new Program().round(i2,i3,i4) > i)
                {
                    Console.WriteLine(new Program().round(i2, i3, i4));
                }
                else
                {
                    Console.WriteLine(i);
                }
            }
        }
    }
}

}
What is wrong with this

You assume that coins can’t be broken down after one step. Take a look at this https://discuss.codechef.com/questions/41032/bytelandian-gold-coin-wrong-answer-why