こんなのは嬉しくないね
var pi =
  (
    (Func<double>)
    (      
      () =>
      {
        const int total = 1000000;
        var inside = 0;
        var rnd = new Random();
        for (int i = 0; i < total; i++)
        {
          var x = rnd.NextDouble() * 2 - 1; var y = rnd.NextDouble() * 2 - 1;
          if (x * x + y * y < 1) inside++;
        }
        return 4.0 * inside / total;
      }
    )
  )();