PREFIX foaf: <http://xmlns.com/foaf/0.1/>
PREFIX vcard: <http://www.w3.org/2001/vcard-rdf/3.0#>
CONSTRUCT {
  ?x vcard:N _:v .
  _:v vcard:givenName ?gname .
  _:v vcard:familyName ?fname .
}
WHERE {
  {
    ?x foaf:firstname ?gname .
  }
  UNION {
    ?x foaf:givenname ?gname .
  }
  {
    ?x foaf:surname ?fname .
  }
  UNION {
    ?x foaf:family_name ?fname .
  }
}