using System;
using System.Text;

public class Test {
	public static void Main()	{
		try {
			string cats = "\uD83D\uDE38\uD83D\uDE3E";
			Console.WriteLine( cats );
			Console.WriteLine( cats.Substring(1) );
			Console.WriteLine( ReverseString(cats) ); //program crashes, generates no output!
			Console.WriteLine( cats.Length );
			
			string noel = "noe\u0308l";
			Console.WriteLine( noel );
			Console.WriteLine( ReverseString(noel) );
			Console.WriteLine( noel.Substring(0,3) );
			Console.WriteLine( noel.Length );
			Console.WriteLine( Join( ",", noel.ToCharArray() ) );

			string ligature = "ba\uFB04e";
			Console.WriteLine( "Upper " + ligature + " => " + ligature.ToUpper() );

			string cnoel = "noël";
			Console.WriteLine( cnoel + " == " + noel + " (" + (cnoel == noel ? "true" : "false") + ")" );
			Console.WriteLine( "Normalize " + cnoel + " == " + noel + " (" + (cnoel.Normalize() == noel.Normalize() ? "true" : "false") + ")" );
			
		} catch( Exception ex ) {
			Console.WriteLine( ex.Message );
		}
	}

    public static string ReverseString(string s) {
		char[] arr = s.ToCharArray();
		Array.Reverse(arr);
		return new string(arr);
    }
    
    public static string Join(string j, char[] cs) {
    	StringBuilder builder = new StringBuilder();
    	foreach( char c in cs ) {
    		builder.Append(c).Append(j);
		}
		return builder.ToString();
    }
}