using System;

using System.Xml.Linq;

using System.Xml.XPath;

public class Program

{

    public static void Main()

    {

        var xml = @"<?xml version=""1.0""?>

<PurchaseOrders>

  <PurchaseOrder PurchaseOrderNumber=""99503"" OrderDate=""1999-10-20"">

    <Address Type=""Shipping"">

      <Name>Ellen Adams</Name>

      <Street>123 Maple Street</Street>

      <City>Mill Valley</City>

      <State>CA</State>

      <Zip>10999</Zip>

      <Country>USA</Country>

    </Address>

    <Address Type=""Billing"">

      <Name>Tai Yee</Name>

      <Street>8 Oak Avenue</Street>

      <City>Old Town</City>

      <State>PA</State>

      <Zip>95819</Zip>

      <Country>USA</Country>

    </Address>

    <DeliveryNotes>Please leave packages in shed by driveway.</DeliveryNotes>

    <Items>

      <Item PartNumber=""872-AA"">

        <ProductName>Lawnmower</ProductName>

        <Quantity>1</Quantity>

        <USPrice>148.95</USPrice>

        <Comment>Confirm this is electric</Comment>

      </Item>

      <Item PartNumber=""926-AA"">

        <ProductName>Baby Monitor</ProductName>

        <Quantity>2</Quantity>

        <USPrice>39.98</USPrice>

        <ShipDate>1999-05-21</ShipDate>

      </Item>

    </Items>

  </PurchaseOrder>

  <PurchaseOrder PurchaseOrderNumber=""99505"" OrderDate=""1999-10-22"">

    <Address Type=""Shipping"">

      <Name>Cristian Osorio</Name>

      <Street>456 Main Street</Street>

      <City>Buffalo</City>

      <State>NY</State>

      <Zip>98112</Zip>

      <Country>USA</Country>

    </Address>

    <Address Type=""Billing"">

      <Name>Cristian Osorio</Name>

      <Street>456 Main Street</Street>

      <City>Buffalo</City>

      <State>NY</State>

      <Zip>98112</Zip>

      <Country>USA</Country>

    </Address>

    <DeliveryNotes>Please notify me before shipping.</DeliveryNotes>

    <Items>

      <Item PartNumber=""456-NM"">

        <ProductName>Power Supply</ProductName>

        <Quantity>1</Quantity>

        <USPrice>45.99</USPrice>

      </Item>

    </Items>

  </PurchaseOrder>

  <PurchaseOrder PurchaseOrderNumber=""99504"" OrderDate=""1999-10-22"">

    <Address Type=""Shipping"">

      <Name>Jessica Arnold</Name>

      <Street>4055 Madison Ave</Street>

      <City>Seattle</City>

      <State>WA</State>

      <Zip>98112</Zip>

      <Country>USA</Country>

    </Address>

    <Address Type=""Billing"">

      <Name>Jessica Arnold</Name>

      <Street>4055 Madison Ave</Street>

      <City>Buffalo</City>

      <State>NY</State>

      <Zip>98112</Zip>

      <Country>USA</Country>

    </Address>

    <Items>

      <Item PartNumber=""898-AZ"">

        <ProductName>Computer Keyboard</ProductName>

        <Quantity>1</Quantity>

        <USPrice>29.99</USPrice>

      </Item>

      <Item PartNumber=""898-AM"">

        <ProductName>Wireless Mouse</ProductName>

        <Quantity>1</Quantity>

        <USPrice>14.99</USPrice>

      </Item>

    </Items>

  </PurchaseOrder>

</PurchaseOrders>";

        var document = XDocument.Parse(xml);

        var elements = document.Root.XPathSelectElements("//PurchaseOrder/Address[@Type=\"Billing\"]");

        foreach (var element in elements)

        {

            Console.WriteLine(element.Element("Name").Value);

        }

    }

}