I want to get the value of artist (Bob Dylan) for title "Greatest Hits" in the xml below
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```
<?xml version="1.0" encoding="ISO-8859-1"?>
<catalog>
  <cd>
    <title>Empire Burlesque</title>
    <artist>Bob Dylan</artist>
    <price>10.90</price>
  </cd>
  <cd>
    <title>Hide your heart</title>
    <artist>Bonnie Tyler</artist>
    <price>10.0</price>
  </cd>
  <cd>
    <title>Greatest Hits</title>
    <artist>Bob Dylan</artist>
    <price>10.90</price>
  </cd>
</catalog>

```