query: SELECT DISTINCT (wd:Q5 as ?item) (COUNT(DISTINCT ?twin) as ?ct)
  {
    ?twin wdt:P31 wd:Q5 .
    ?twin wdt:P1889 [] .
    ?twin p:P1889/pq:P1013 wd:Q20978290 .
    MINUS { ?item wdt:P31 wd:Q159979 }
  }
  GROUP BY ?item