how Get parent OU of child ou in Active Directory using C#?

DirectoryEntry user = null;
DirectoryEntry gcEntry = new DirectoryEntry("GC:");

IEnumerator ie = gcEntry.Children.GetEnumerator();

while (ie.MoveNext())
{

    gcEntry = (DirectoryEntry)ie.Current;

}

using (DirectorySearcher searcher = new DirectorySearcher(gcEntry))
{
   searcher.Filter = string.Format(ldapQueryString);
   SearchResult result = searcher.FindOne();
   string[] pathParts = user.Path.Split(new char[] { ',', ' ' });
}