What is the island nation with the lowest marriageable age whose member of is United Nations Educational, Scientific and Cultural Organization?
select ?ent where { ?ent wdt:P31 wd:Q112099 . ?ent wdt:P3000 ?obj . ?ent wdt:P463 wd:Q7809} ORDER BY ASC(?obj)LIMIT 5 
island nation: Q112099 unesco: Q7809