using System;

namespace a
{
	
	public abstract class Logger {
		public abstract void Write (string s);
		
		
		public virtual string GetVersion() {
			return "LoggerBase 1.0";
		}
	}
	
	public abstract class NormalLogger : Logger {
		public override void Write( string s){
			Console.WriteLine(s);
		}
		
		public override string GetVersion() {
			return "NormalLogger 1.0";
		}
	}
	
	public abstract class ColorLogger : Logger {
		public override void Write( string s){
			Console.WriteLine(s);
		}
		
		public override string GetVersion() {
			Console.ForegroundColor = ConsoleColor.DarkBlue;
			return "ColoredLogger 1.0";
		}
	}
	
	class LoggerService {
		
		public LoggerService(Logger a){
			
		}
		public string Log(string l) {
				
		}
			
		public void Version(){
				
		}
		
	}
	
	class Program
	{
		public static void Main(string[] args)
		{
			LoggerService ls = new LoggerService();
			
			Console.ReadKey();
		}
	}
	
}