tell  me province of China that capital Chengdu  starts with letter s
SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q1615742 . ?sbj wdt:P36 wd:Q30002 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 's')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
province of china: Q1615742 chengdu: Q30002