using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        String sample = "deqn1-2";

        Regex regex = new Regex("deqn(?:(?<match1>\\d+)-(?<match2>\\d+)|(?<match1>\\d+\\w+)-(?<match2>\\d+\\w+))\\b");

​

        Match match = regex.Match(sample);

​

        if (match.Success)

        {

            Console.WriteLine(match.Groups["match1"].Value);

            Console.WriteLine(match.Groups["match2"].Value);

        }

    }

}