using System;

using System.Text.RegularExpressions;

public class Program

{

    public static void Main()

    {

        string html = "<br />\n" +

            "Your coupon for 50% off MSRP - Inline is: XXXXXXXXXXX<br />" +

            "Your coupon for 50% off MSRP - Outdoor is: XXXXXXXXXXX<br /><br />";

        MatchCollection matches = Regex.Matches(html, ".*?coupon.*?(?<=: )(\\w+)(?=<br />|<br/>)");

        foreach (Match match in matches)

        {

            Console.WriteLine(match.Groups[1]);

        }

    }

}