What are the regional organization that shares border with the Central African Republic and which that starts with the letter a
SELECT DISTINCT ?sbj ?sbj_label WHERE { ?sbj wdt:P31 wd:Q4120211 . ?sbj wdt:P47 wd:Q929 . ?sbj rdfs:label ?sbj_label . FILTER(STRSTARTS(lcase(?sbj_label), 'a')) . FILTER (lang(?sbj_label) = 'en') } LIMIT 25 
regional organization: Q4120211 central african republic: Q929