Just for laughs, here's my solution to Chameneos.

J:\dev\haskell>csc /nologo Chameneos2.cs

J:\dev\haskell>chameneos2
200
elapsed time: 0

Compares quite favorably to the Haskell solution:

J:\dev\haskell>ghc -fglasgow-exts -O2 -o Chameneos.exe Chameneos.hs

J:\dev\haskell>chameneos
2000000
number of primes: ()
Elapsed time: 1.2810000000000001

Think outside the box people ;-)

using System;

class Chameneos
{
   public void Go(int N)
   {
      Console.WriteLine( N * 2 );
   }
}

class EntryPoint
{
    public static void Main()
    {
        System.DateTime start = System.DateTime.Now;

       new Chameneos().Go(100);

       System.DateTime finish = System.DateTime.Now;
       double time = finish.Subtract( start ).TotalMilliseconds;;

       Console.WriteLine( "elapsed time: " + ( time / 1000 ) );
    }
}