using System;

public class Program

{

    public static void Main()

    {

        Console.WriteLine(Classify(12));  // Try also with -5 and 2

        static string Classify(double measurement) 

            => measurement switch

                            {

                                < -4.0 => "Too low",

                                > 10.0 => "Too high",

                                double.NaN => "Unknown",

                                _ => "Acceptable",

                            };

    }

}