query: SELECT ?item ?itemLabel
  WHERE
  {
  	?item wdt:P31 wd:Q5 . 
    	OPTIONAL { ?item wdt:P735 ?dummy0 } 
    	FILTER(!bound(?dummy0))	
  	FILTER(STRSTARTS(?itemLabel, 'John ')) .
  	SERVICE wikibase:label {
  		bd:serviceParam wikibase:language "en" .
  		?item rdfs:label ?itemLabel .
  	}
  }