using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;
namespace CATesting
{
    class Program
    {
        static void Main(string[] args)
        {
            string str = "-1832jskfksHJaklfdk89skl7kks-";
            Regex re = new Regex(@"^[-0-9a-zA-Z]*$", RegexOptions.IgnoreCase);
            if (!re.IsMatch(str))
            {
                str = string.Empty;
            }
            Console.WriteLine(str);
            Console.ReadKey();
        }
    }
}