using System;
using System.Text.RegularExpressions;

public class RegEx
{
    public static void Main()
    {
        string pattern = @"(?<=cn=)[\w\s]+(?=\\ou.*?$)";
        string input = @"ou=company\ou=country\ou=site\cn=office\cn=name\ou=pet";
        
        foreach (Match m in Regex.Matches(input, pattern))
        {
            Console.WriteLine("{0}", m.Value);
        }
    }
}