<?xml version="1.0" ?>
<xsl:stylesheet version="1.0"
 xmlns:xsl="http://www.w3.org/1999/XSL/Transform">
<xsl:key name="movies-by-key" match="record" use="key" />
<xsl:template match="root">
<root>
    <xsl:for-each
select="record[count(. | key('movies-by-key', key)[1]) = 1]">


<record>
<key>
<xsl:value-of select="key" />
</key>
<movies>

        <xsl:for-each select="key('movies-by-key', key)">

<movie>
            <xsl:value-of select="movie" />
</movie>

        </xsl:for-each>
</movies>
</record>
    </xsl:for-each>
</root>
</xsl:template>
</xsl:stylesheet>