XSD Code: getting error- the content model of complex type definition ' anonymous ' is ambiguous
<xs:element name="data">
<xs:complexType>
<xs:choice>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="A"/>
<xs:element name="B"/>
<xs:element name="C"/>
<xs:element name="D"/>
<xs:element name="EE"/>
</xs:choice>
<xs:choice minOccurs="0" maxOccurs="unbounded">
<xs:element name="A"/>
<xs:element name="B"/>
<xs:element name="C"/>
<xs:element name="D"/>
<xs:element name="FF"/>
</xs:choice>
</xs:choice>
</xs:complexType>
</xs:element>