using System;

using System.Linq;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

​

        string str = "FoOb@R".ToUpper();

        Regex r = new Regex("[ABCDEFGHIJKLMNOPQRSTUVWXYZ$_/+-.0123456789]");

        String result = r.Replace(str, "-");

        Console.WriteLine(result);

    }

}