Country Coordinate Finder Update

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Xml;
using System.IO;
using System.Xml.Linq;

namespace CountryTest
{
    public class Kml
    {
        public List<Country> Countries { get; private set; }

        public Kml(String kml)
        {
            this.Countries = new List<Country>();

            XElement xElement = XElement.Parse(kml);

            var placemarks = xElement.Elements().First().Elements(XName.Get("{http://earth.google.com/kml/2.2}Placemark"));

            foreach (var p in placemarks)
            {
                var extendedData = p.Element(XName.Get("{http://earth.google.com/kml/2.2}ExtendedData")).Elements();

                string name = "";

                foreach (var dataElement in extendedData)
                {
                    var a = dataElement.Attribute(XName.Get("name")).Value;
                    if (a == "NAME")
                    {
                        name = dataElement.Element(XName.Get("{http://earth.google.com/kml/2.2}value")).Value.Replace("<![CDATA[", "").Replace("]]>", "");
                    }
                }

                var multiGeometry = p.Element(XName.Get("{http://earth.google.com/kml/2.2}MultiGeometry")).Elements().ToList();

                List<Polygon> outerPolygons = new List<Polygon>();
                List<Polygon> innerPolygons = new List<Polygon>();

                var n = multiGeometry.First().Name;

                if (multiGeometry.First().Name == XName.Get("{http://earth.google.com/kml/2.2}Polygon"))
                {
                    var polygonString = multiGeometry.Elements().First().Elements().First().Elements().First().Value.Replace("\n","");
                    outerPolygons.Add(new Polygon(polygonString));
                }
                else
                {
                    var polygons = multiGeometry.Elements();

                    foreach (var polygon in polygons)
                    {
                        var type = polygon.Elements().First().Name;
                        if (type == XName.Get("{http://earth.google.com/kml/2.2}outerBoundaryIs"))
                        {
                            var polygonString = polygon.Elements().First().Value.Replace("\n", "");
                            outerPolygons.Add(new Polygon(polygonString));
                        }
                        else if (type == XName.Get("{http://earth.google.com/kml/2.2}innerBoundaryIs"))
                        {
                            var polygonString = polygon.Elements().First().Value.Replace("\n", "");
                            innerPolygons.Add(new Polygon(polygonString));
                        }
                    }
                }

                Countries.Add(new Country(name, outerPolygons, innerPolygons));
            }
        }

        public String GetCountryByCoordinates(double x, double y)
        {
            foreach (Country c in Countries)
                if (c.ContainsPoint(x, y))
                    return c.Name;

            return "";
        }
    }

    public class Country
    {
        public String Name { get; private set; }

        List<Polygon> _outerPolygons;
        List<Polygon> _innerPolygons;

        public Country(String name, List<Polygon> outerPolygons, List<Polygon> innerPolygons)
        {
            this.Name = name;
            _outerPolygons = outerPolygons;
            _innerPolygons = innerPolygons;
        }

        public bool ContainsPoint(double x, double y)
        {
            foreach (Polygon inner in _innerPolygons)
                if (inner.ContainsPoint(x, y))
                    return false;

            foreach (Polygon outer in _outerPolygons)
                if (outer.ContainsPoint(x, y))
                    return true;

            return false;
        }
    }

    public class Polygon
    {
        List<Tuple<double, double>> _coordinates;
        public Polygon(String kmlPolygonString)
        {
            _coordinates = new List<Tuple<double, double>>();

            string[] points = kmlPolygonString.Split(' ');

            foreach (string s in points)
            {
                string[] parts = s.Split(',');
                double x = double.Parse(parts[0], System.Globalization.CultureInfo.InvariantCulture);
                double y = double.Parse(parts[1], System.Globalization.CultureInfo.InvariantCulture);

                _coordinates.Add(new Tuple<double, double>(x, y));
            }
        }

        //modified from source: http://stackoverflow.com/a/2922778/1020861
        public bool ContainsPoint(double x, double y)
        {
            int i, j;
            bool c = false;
            for (i = 0, j = _coordinates.Count - 1; i < _coordinates.Count; j = i++)
            {
                if (((_coordinates[i].Item2 > y) != (_coordinates[j].Item2 > y)) &&
                 (x < (_coordinates[j].Item1 - _coordinates[i].Item1) * (y - _coordinates[i].Item2) / (_coordinates[j].Item2 - _coordinates[i].Item2) + _coordinates[i].Item1))
                    c = !c;
            }
            return c;
        }
    }
}