Linq to xml select most frequent value

I need to select the most frequest occurrence of an value in a linq to xml collection of elements. How do you do that?

Edit, Here is what i tried but its obviously not correct;

 XDocument btC开发者_如何学Goheck = XDocument.Load("https://www.url.com" + postcode);

var districtCode = btCheck.Descendants("DSL_CHECKER").Elements("ADDRESS_DETAILS").Elements("ADDRESS_DETAIL").Elements("ADDRESS").Elements("DISTRICTID");

  string d = (districtCode.GroupBy(z => z.Value).OrderBy(z => z.Key).Take(1)).First();

As you don't show what you tried so far, I will just give some hints instead of a full answer:
GroupBy and then Max.

        var code = btCheck.Descendants("ADSL_CHECKER").Elements("ADDRESS_DETAILS")
            .Elements("ADDRESS_DETAIL").Elements("ADDRESS").Elements("DISTRICTID")
            .GroupBy(z => z.Value).Select(group => new
            {
                value = group.Key,
                Count = group.Count()
            })
            .OrderByDescending(z => z.Count).FirstOrDefault();