using System;

using System.Text.RegularExpressions;

​

public class Program

{

    public static void Main()

    {

        Regex regex = new Regex(@"^(?=.*?[0-9])|(?=.*?[^A-Za-z0-9 ]).*$");

        Match match = regex.Match("test1");

        if (match.Success)

        {

            Console.WriteLine("MATCHED");

        }else{

            Console.WriteLine("NOT MATCHED");

        }

    }

}

​