Calculator prototype

Calcluaotr_prototype.cs

// program.cs
static void Main(string[] args)
{
    const string WELCOME = "Welcome to Calculator. Feel free to type any expression you want.";
    const string PROMPT = ">> ";
    Console.Out.Write(WELCOME + Environment.NewLine);
    while(true)
    {
        Console.Out.Write(PROMPT);
        try
        {
            var input = Console.In.ReadLine();
            if(string.Compare(input, "exit", StringComparison.OrdinalIgnoreCase) == 0)
            {
                break;
            }
            Console.Out.Write(input);
            Console.Out.Write(Environment.NewLine);
        }
       catch(Exception e)
       {
            Console.Out.Write("Oops! Something seems to go wrong." + Environment.NewLine);
            Console.Out.Write(e.Message);
            Console.Out.Write(Environment.NewLine);
        }
      }
}