using System;


[Serializable]
public sealed class MailReceivedEventArgs : EventArgs {
    private readonly string from;
    private readonly string subject;

    public MailReceivedEventArgs(string from, string subject) {
        this.from = from;
        this.subject = subject;
    }

    public string From { get { return from; } }
    public string Subject { get { return subject; } }
}

public class MainClass {
    public static void Main() {
        MailReceivedEventArgs args = new MailReceivedEventArgs("D", "Y");
        Console.WriteLine("From: {0}, Subject: {1}", args.From, args.Subject);
    }
}

    

   
 

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


  internal class OSHelper
  {
    internal static bool Is2003VistaOrGreater { get { return Environment.OSVersion.Version.CompareTo(new Version(5, 2)) >= 0; } }
    internal static bool IsVistaOrGreater { get { return Environment.OSVersion.Version.CompareTo(new Version(6, 0)) >= 0; } }
  }

   
     

   
  

using System;

class MainClass {
    public static void Main() {
        Console.WriteLine("System folder : " + Environment.SystemDirectory);
    }
}

   
     

   
  

using System;

class MainClass {
    public static void Main() {
        Console.WriteLine("Current folder : " + Environment.CurrentDirectory);
    }
}

   
     

   
  

using System;

class MainClass {
    public static void Main() {
        foreach (string s in Environment.GetLogicalDrives()) {
            Console.WriteLine("Logical drive : " + s);
        }
    }
}

   
     

   
  

using System;

class MainClass {
    public static void Main() {
        Console.WriteLine("Ticks since startup : " + Environment.TickCount);
    }
}

   
     

   
  

using System;

class MainClass {
    public static void Main() {
        Console.WriteLine("Shutting down? : " + Environment.HasShutdownStarted);
    }
}