Tell me the major party which holds the office as head of the organisation by the chairman of the Social Democratic Party and whose name contains the word democratic?
SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q6738353 . ?sbj wdt:P2388 wd:Q29576752 . ?sbj rdfs:label ?sbj_label . FILTER(CONTAINS(lcase(?sbj_label), 'democratic')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
major party: Q6738353 chairman of the social democratic party: Q29576752